2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 - Intel Monahans options:
542 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
544 Defines the Monahans run mode to oscillator
545 ratio. Valid values are 8, 16, 24, 31. The core
546 frequency is this value multiplied by 13 MHz.
548 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
550 Defines the Monahans turbo mode to oscillator
551 ratio. Valid values are 1 (default if undefined) and
552 2. The core frequency as calculated above is multiplied
556 CONFIG_SYS_INIT_SP_OFFSET
558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
559 pointer. This is needed for the temporary stack before
562 CONFIG_SYS_MIPS_CACHE_MODE
564 Cache operation mode for the MIPS CPU.
565 See also arch/mips/include/asm/mipsregs.h.
567 CONF_CM_CACHABLE_NO_WA
570 CONF_CM_CACHABLE_NONCOHERENT
574 CONF_CM_CACHABLE_ACCELERATED
576 CONFIG_SYS_XWAY_EBU_BOOTCFG
578 Special option for Lantiq XWAY SoCs for booting from NOR flash.
579 See also arch/mips/cpu/mips32/start.S.
581 CONFIG_XWAY_SWAP_BYTES
583 Enable compilation of tools/xway-swap-bytes needed for Lantiq
584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
585 be swapped if a flash programmer is used.
588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
590 Select high exception vectors of the ARM core, e.g., do not
591 clear the V bit of the c1 register of CP15.
593 CONFIG_SYS_THUMB_BUILD
595 Use this flag to build U-Boot using the Thumb instruction
596 set for ARM architectures. Thumb instruction set provides
597 better code density. For ARM architectures that support
598 Thumb2 this flag will result in Thumb2 code generated by
601 CONFIG_ARM_ERRATA_716044
602 CONFIG_ARM_ERRATA_742230
603 CONFIG_ARM_ERRATA_743622
604 CONFIG_ARM_ERRATA_751472
605 CONFIG_ARM_ERRATA_794072
606 CONFIG_ARM_ERRATA_761320
608 If set, the workarounds for these ARM errata are applied early
609 during U-Boot startup. Note that these options force the
610 workarounds to be applied; no CPU-type/version detection
611 exists, unlike the similar options in the Linux kernel. Do not
612 set these options unless they apply!
617 The frequency of the timer returned by get_timer().
618 get_timer() must operate in milliseconds and this CONFIG
619 option must be set to 1000.
621 - Linux Kernel Interface:
624 U-Boot stores all clock information in Hz
625 internally. For binary compatibility with older Linux
626 kernels (which expect the clocks passed in the
627 bd_info data to be in MHz) the environment variable
628 "clocks_in_mhz" can be defined so that U-Boot
629 converts clock data to MHZ before passing it to the
631 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
632 "clocks_in_mhz=1" is automatically included in the
635 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
637 When transferring memsize parameter to linux, some versions
638 expect it to be in bytes, others in MB.
639 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
643 New kernel versions are expecting firmware settings to be
644 passed using flattened device trees (based on open firmware
648 * New libfdt-based support
649 * Adds the "fdt" command
650 * The bootm command automatically updates the fdt
652 OF_CPU - The proper name of the cpus node (only required for
653 MPC512X and MPC5xxx based boards).
654 OF_SOC - The proper name of the soc node (only required for
655 MPC512X and MPC5xxx based boards).
656 OF_TBCLK - The timebase frequency.
657 OF_STDOUT_PATH - The path to the console device
659 boards with QUICC Engines require OF_QE to set UCC MAC
662 CONFIG_OF_BOARD_SETUP
664 Board code has addition modification that it wants to make
665 to the flat device tree before handing it off to the kernel
669 This define fills in the correct boot CPU in the boot
670 param header, the default value is zero if undefined.
674 U-Boot can detect if an IDE device is present or not.
675 If not, and this new config option is activated, U-Boot
676 removes the ATA node from the DTS before booting Linux,
677 so the Linux IDE driver does not probe the device and
678 crash. This is needed for buggy hardware (uc101) where
679 no pull down resistor is connected to the signal IDE5V_DD7.
681 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
683 This setting is mandatory for all boards that have only one
684 machine type and must be used to specify the machine type
685 number as it appears in the ARM machine registry
686 (see http://www.arm.linux.org.uk/developer/machines/).
687 Only boards that have multiple machine types supported
688 in a single configuration file and the machine type is
689 runtime discoverable, do not have to use this setting.
691 - vxWorks boot parameters:
693 bootvx constructs a valid bootline using the following
694 environments variables: bootfile, ipaddr, serverip, hostname.
695 It loads the vxWorks image pointed bootfile.
697 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
698 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
699 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
700 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
702 CONFIG_SYS_VXWORKS_ADD_PARAMS
704 Add it at the end of the bootline. E.g "u=username pw=secret"
706 Note: If a "bootargs" environment is defined, it will overwride
707 the defaults discussed just above.
709 - Cache Configuration:
710 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
711 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
712 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
714 - Cache Configuration for ARM:
715 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
717 CONFIG_SYS_PL310_BASE - Physical base address of PL310
718 controller register space
723 Define this if you want support for Amba PrimeCell PL010 UARTs.
727 Define this if you want support for Amba PrimeCell PL011 UARTs.
731 If you have Amba PrimeCell PL011 UARTs, set this variable to
732 the clock speed of the UARTs.
736 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
737 define this to a list of base addresses for each (supported)
738 port. See e.g. include/configs/versatile.h
740 CONFIG_PL011_SERIAL_RLCR
742 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
743 have separate receive and transmit line control registers. Set
744 this variable to initialize the extra register.
746 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
748 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
749 boot loader that has already initialized the UART. Define this
750 variable to flush the UART at init time.
752 CONFIG_SERIAL_HW_FLOW_CONTROL
754 Define this variable to enable hw flow control in serial driver.
755 Current user of this option is drivers/serial/nsl16550.c driver
758 Depending on board, define exactly one serial port
759 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
760 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
761 console by defining CONFIG_8xx_CONS_NONE
763 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
764 port routines must be defined elsewhere
765 (i.e. serial_init(), serial_getc(), ...)
768 Enables console device for a color framebuffer. Needs following
769 defines (cf. smiLynxEM, i8042)
770 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
772 VIDEO_HW_RECTFILL graphic chip supports
775 VIDEO_HW_BITBLT graphic chip supports
776 bit-blit (cf. smiLynxEM)
777 VIDEO_VISIBLE_COLS visible pixel columns
779 VIDEO_VISIBLE_ROWS visible pixel rows
780 VIDEO_PIXEL_SIZE bytes per pixel
781 VIDEO_DATA_FORMAT graphic data format
782 (0-5, cf. cfb_console.c)
783 VIDEO_FB_ADRS framebuffer address
784 VIDEO_KBD_INIT_FCT keyboard int fct
785 (i.e. i8042_kbd_init())
786 VIDEO_TSTC_FCT test char fct
788 VIDEO_GETC_FCT get char fct
790 CONFIG_CONSOLE_CURSOR cursor drawing on/off
791 (requires blink timer
793 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
794 CONFIG_CONSOLE_TIME display time/date info in
796 (requires CONFIG_CMD_DATE)
797 CONFIG_VIDEO_LOGO display Linux logo in
799 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
800 linux_logo.h for logo.
801 Requires CONFIG_VIDEO_LOGO
802 CONFIG_CONSOLE_EXTRA_INFO
803 additional board info beside
806 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
807 a limited number of ANSI escape sequences (cursor control,
808 erase functions and limited graphics rendition control).
810 When CONFIG_CFB_CONSOLE is defined, video console is
811 default i/o. Serial console can be forced with
812 environment 'console=serial'.
814 When CONFIG_SILENT_CONSOLE is defined, all console
815 messages (by U-Boot and Linux!) can be silenced with
816 the "silent" environment variable. See
817 doc/README.silent for more information.
819 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
821 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
825 CONFIG_BAUDRATE - in bps
826 Select one of the baudrates listed in
827 CONFIG_SYS_BAUDRATE_TABLE, see below.
828 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
830 - Console Rx buffer length
831 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
832 the maximum receive buffer length for the SMC.
833 This option is actual only for 82xx and 8xx possible.
834 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
835 must be defined, to setup the maximum idle timeout for
838 - Pre-Console Buffer:
839 Prior to the console being initialised (i.e. serial UART
840 initialised etc) all console output is silently discarded.
841 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
842 buffer any console messages prior to the console being
843 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
844 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
845 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
846 bytes are output before the console is initialised, the
847 earlier bytes are discarded.
849 'Sane' compilers will generate smaller code if
850 CONFIG_PRE_CON_BUF_SZ is a power of 2
852 - Safe printf() functions
853 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
854 the printf() functions. These are defined in
855 include/vsprintf.h and include snprintf(), vsnprintf() and
856 so on. Code size increase is approximately 300-500 bytes.
857 If this option is not given then these functions will
858 silently discard their buffer size argument - this means
859 you are not getting any overflow checking in this case.
861 - Boot Delay: CONFIG_BOOTDELAY - in seconds
862 Delay before automatically booting the default image;
863 set to -1 to disable autoboot.
864 set to -2 to autoboot with no delay and not check for abort
865 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
867 See doc/README.autoboot for these options that
868 work with CONFIG_BOOTDELAY. None are required.
869 CONFIG_BOOT_RETRY_TIME
870 CONFIG_BOOT_RETRY_MIN
871 CONFIG_AUTOBOOT_KEYED
872 CONFIG_AUTOBOOT_PROMPT
873 CONFIG_AUTOBOOT_DELAY_STR
874 CONFIG_AUTOBOOT_STOP_STR
875 CONFIG_AUTOBOOT_DELAY_STR2
876 CONFIG_AUTOBOOT_STOP_STR2
877 CONFIG_ZERO_BOOTDELAY_CHECK
878 CONFIG_RESET_TO_RETRY
882 Only needed when CONFIG_BOOTDELAY is enabled;
883 define a command string that is automatically executed
884 when no character is read on the console interface
885 within "Boot Delay" after reset.
888 This can be used to pass arguments to the bootm
889 command. The value of CONFIG_BOOTARGS goes into the
890 environment value "bootargs".
892 CONFIG_RAMBOOT and CONFIG_NFSBOOT
893 The value of these goes into the environment as
894 "ramboot" and "nfsboot" respectively, and can be used
895 as a convenience, when switching between booting from
899 CONFIG_BOOTCOUNT_LIMIT
900 Implements a mechanism for detecting a repeating reboot
902 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
905 If no softreset save registers are found on the hardware
906 "bootcount" is stored in the environment. To prevent a
907 saveenv on all reboots, the environment variable
908 "upgrade_available" is used. If "upgrade_available" is
909 0, "bootcount" is always 0, if "upgrade_available" is
910 1 "bootcount" is incremented in the environment.
911 So the Userspace Applikation must set the "upgrade_available"
912 and "bootcount" variable to 0, if a boot was successfully.
917 When this option is #defined, the existence of the
918 environment variable "preboot" will be checked
919 immediately before starting the CONFIG_BOOTDELAY
920 countdown and/or running the auto-boot command resp.
921 entering interactive mode.
923 This feature is especially useful when "preboot" is
924 automatically generated or modified. For an example
925 see the LWMON board specific code: here "preboot" is
926 modified when the user holds down a certain
927 combination of keys on the (special) keyboard when
930 - Serial Download Echo Mode:
932 If defined to 1, all characters received during a
933 serial download (using the "loads" command) are
934 echoed back. This might be needed by some terminal
935 emulations (like "cu"), but may as well just take
936 time on others. This setting #define's the initial
937 value of the "loads_echo" environment variable.
939 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
941 Select one of the baudrates listed in
942 CONFIG_SYS_BAUDRATE_TABLE, see below.
945 Monitor commands can be included or excluded
946 from the build by using the #include files
947 <config_cmd_all.h> and #undef'ing unwanted
948 commands, or using <config_cmd_default.h>
949 and augmenting with additional #define's
952 The default command configuration includes all commands
953 except those marked below with a "*".
955 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
956 CONFIG_CMD_ASKENV * ask for env variable
957 CONFIG_CMD_BDI bdinfo
958 CONFIG_CMD_BEDBUG * Include BedBug Debugger
959 CONFIG_CMD_BMP * BMP support
960 CONFIG_CMD_BSP * Board specific commands
961 CONFIG_CMD_BOOTD bootd
962 CONFIG_CMD_CACHE * icache, dcache
963 CONFIG_CMD_CLK * clock command support
964 CONFIG_CMD_CONSOLE coninfo
965 CONFIG_CMD_CRC32 * crc32
966 CONFIG_CMD_DATE * support for RTC, date/time...
967 CONFIG_CMD_DHCP * DHCP support
968 CONFIG_CMD_DIAG * Diagnostics
969 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
970 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
971 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
972 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
973 CONFIG_CMD_DTT * Digital Therm and Thermostat
974 CONFIG_CMD_ECHO echo arguments
975 CONFIG_CMD_EDITENV edit env variable
976 CONFIG_CMD_EEPROM * EEPROM read/write support
977 CONFIG_CMD_ELF * bootelf, bootvx
978 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
979 CONFIG_CMD_ENV_FLAGS * display details about env flags
980 CONFIG_CMD_ENV_EXISTS * check existence of env variable
981 CONFIG_CMD_EXPORTENV * export the environment
982 CONFIG_CMD_EXT2 * ext2 command support
983 CONFIG_CMD_EXT4 * ext4 command support
984 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
985 that work for multiple fs types
986 CONFIG_CMD_SAVEENV saveenv
987 CONFIG_CMD_FDC * Floppy Disk Support
988 CONFIG_CMD_FAT * FAT command support
989 CONFIG_CMD_FLASH flinfo, erase, protect
990 CONFIG_CMD_FPGA FPGA device initialization support
991 CONFIG_CMD_FUSE * Device fuse support
992 CONFIG_CMD_GETTIME * Get time since boot
993 CONFIG_CMD_GO * the 'go' command (exec code)
994 CONFIG_CMD_GREPENV * search environment
995 CONFIG_CMD_HASH * calculate hash / digest
996 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
997 CONFIG_CMD_I2C * I2C serial bus support
998 CONFIG_CMD_IDE * IDE harddisk support
999 CONFIG_CMD_IMI iminfo
1000 CONFIG_CMD_IMLS List all images found in NOR flash
1001 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1002 CONFIG_CMD_IMMAP * IMMR dump support
1003 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1004 CONFIG_CMD_IMPORTENV * import an environment
1005 CONFIG_CMD_INI * import data from an ini file into the env
1006 CONFIG_CMD_IRQ * irqinfo
1007 CONFIG_CMD_ITEST Integer/string test of 2 values
1008 CONFIG_CMD_JFFS2 * JFFS2 Support
1009 CONFIG_CMD_KGDB * kgdb
1010 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1011 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1013 CONFIG_CMD_LOADB loadb
1014 CONFIG_CMD_LOADS loads
1015 CONFIG_CMD_MD5SUM * print md5 message digest
1016 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1017 CONFIG_CMD_MEMINFO * Display detailed memory information
1018 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1020 CONFIG_CMD_MEMTEST * mtest
1021 CONFIG_CMD_MISC Misc functions like sleep etc
1022 CONFIG_CMD_MMC * MMC memory mapped support
1023 CONFIG_CMD_MII * MII utility commands
1024 CONFIG_CMD_MTDPARTS * MTD partition support
1025 CONFIG_CMD_NAND * NAND support
1026 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1027 CONFIG_CMD_NFS NFS support
1028 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1029 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1030 CONFIG_CMD_PCI * pciinfo
1031 CONFIG_CMD_PCMCIA * PCMCIA support
1032 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1034 CONFIG_CMD_PORTIO * Port I/O
1035 CONFIG_CMD_READ * Read raw data from partition
1036 CONFIG_CMD_REGINFO * Register dump
1037 CONFIG_CMD_RUN run command in env variable
1038 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1039 CONFIG_CMD_SAVES * save S record dump
1040 CONFIG_CMD_SCSI * SCSI Support
1041 CONFIG_CMD_SDRAM * print SDRAM configuration information
1042 (requires CONFIG_CMD_I2C)
1043 CONFIG_CMD_SETGETDCR Support for DCR Register access
1045 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1046 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1047 (requires CONFIG_CMD_MEMORY)
1048 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1049 CONFIG_CMD_SOURCE "source" command Support
1050 CONFIG_CMD_SPI * SPI serial bus support
1051 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1052 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1053 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1054 CONFIG_CMD_TIMER * access to the system tick timer
1055 CONFIG_CMD_USB * USB support
1056 CONFIG_CMD_CDP * Cisco Discover Protocol support
1057 CONFIG_CMD_MFSL * Microblaze FSL support
1058 CONFIG_CMD_XIMG Load part of Multi Image
1059 CONFIG_CMD_UUID * Generate random UUID or GUID string
1061 EXAMPLE: If you want all functions except of network
1062 support you can write:
1064 #include "config_cmd_all.h"
1065 #undef CONFIG_CMD_NET
1068 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1070 Note: Don't enable the "icache" and "dcache" commands
1071 (configuration option CONFIG_CMD_CACHE) unless you know
1072 what you (and your U-Boot users) are doing. Data
1073 cache cannot be enabled on systems like the 8xx or
1074 8260 (where accesses to the IMMR region must be
1075 uncached), and it cannot be disabled on all other
1076 systems where we (mis-) use the data cache to hold an
1077 initial stack and some data.
1080 XXX - this list needs to get updated!
1082 - Regular expression support:
1084 If this variable is defined, U-Boot is linked against
1085 the SLRE (Super Light Regular Expression) library,
1086 which adds regex support to some commands, as for
1087 example "env grep" and "setexpr".
1091 If this variable is defined, U-Boot will use a device tree
1092 to configure its devices, instead of relying on statically
1093 compiled #defines in the board file. This option is
1094 experimental and only available on a few boards. The device
1095 tree is available in the global data as gd->fdt_blob.
1097 U-Boot needs to get its device tree from somewhere. This can
1098 be done using one of the two options below:
1101 If this variable is defined, U-Boot will embed a device tree
1102 binary in its image. This device tree file should be in the
1103 board directory and called <soc>-<board>.dts. The binary file
1104 is then picked up in board_init_f() and made available through
1105 the global data structure as gd->blob.
1108 If this variable is defined, U-Boot will build a device tree
1109 binary. It will be called u-boot.dtb. Architecture-specific
1110 code will locate it at run-time. Generally this works by:
1112 cat u-boot.bin u-boot.dtb >image.bin
1114 and in fact, U-Boot does this for you, creating a file called
1115 u-boot-dtb.bin which is useful in the common case. You can
1116 still use the individual files if you need something more
1121 If this variable is defined, it enables watchdog
1122 support for the SoC. There must be support in the SoC
1123 specific code for a watchdog. For the 8xx and 8260
1124 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1125 register. When supported for a specific SoC is
1126 available, then no further board specific code should
1127 be needed to use it.
1130 When using a watchdog circuitry external to the used
1131 SoC, then define this variable and provide board
1132 specific code for the "hw_watchdog_reset" function.
1135 CONFIG_VERSION_VARIABLE
1136 If this variable is defined, an environment variable
1137 named "ver" is created by U-Boot showing the U-Boot
1138 version as printed by the "version" command.
1139 Any change to this variable will be reverted at the
1144 When CONFIG_CMD_DATE is selected, the type of the RTC
1145 has to be selected, too. Define exactly one of the
1148 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1149 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1150 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1151 CONFIG_RTC_MC146818 - use MC146818 RTC
1152 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1153 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1154 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1155 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1156 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1157 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1158 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1159 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1160 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1163 Note that if the RTC uses I2C, then the I2C interface
1164 must also be configured. See I2C Support, below.
1167 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1169 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1170 chip-ngpio pairs that tell the PCA953X driver the number of
1171 pins supported by a particular chip.
1173 Note that if the GPIO device uses I2C, then the I2C interface
1174 must also be configured. See I2C Support, below.
1177 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1178 accesses and can checksum them or write a list of them out
1179 to memory. See the 'iotrace' command for details. This is
1180 useful for testing device drivers since it can confirm that
1181 the driver behaves the same way before and after a code
1182 change. Currently this is supported on sandbox and arm. To
1183 add support for your architecture, add '#include <iotrace.h>'
1184 to the bottom of arch/<arch>/include/asm/io.h and test.
1186 Example output from the 'iotrace stats' command is below.
1187 Note that if the trace buffer is exhausted, the checksum will
1188 still continue to operate.
1191 Start: 10000000 (buffer start address)
1192 Size: 00010000 (buffer size)
1193 Offset: 00000120 (current buffer offset)
1194 Output: 10000120 (start + offset)
1195 Count: 00000018 (number of trace records)
1196 CRC32: 9526fb66 (CRC32 of all trace records)
1198 - Timestamp Support:
1200 When CONFIG_TIMESTAMP is selected, the timestamp
1201 (date and time) of an image is printed by image
1202 commands like bootm or iminfo. This option is
1203 automatically enabled when you select CONFIG_CMD_DATE .
1205 - Partition Labels (disklabels) Supported:
1206 Zero or more of the following:
1207 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1208 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1209 Intel architecture, USB sticks, etc.
1210 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1211 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1212 bootloader. Note 2TB partition limit; see
1214 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1216 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1217 CONFIG_CMD_SCSI) you must configure support for at
1218 least one non-MTD partition type as well.
1221 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1222 board configurations files but used nowhere!
1224 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1225 be performed by calling the function
1226 ide_set_reset(int reset)
1227 which has to be defined in a board specific file
1232 Set this to enable ATAPI support.
1237 Set this to enable support for disks larger than 137GB
1238 Also look at CONFIG_SYS_64BIT_LBA.
1239 Whithout these , LBA48 support uses 32bit variables and will 'only'
1240 support disks up to 2.1TB.
1242 CONFIG_SYS_64BIT_LBA:
1243 When enabled, makes the IDE subsystem use 64bit sector addresses.
1247 At the moment only there is only support for the
1248 SYM53C8XX SCSI controller; define
1249 CONFIG_SCSI_SYM53C8XX to enable it.
1251 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1252 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1253 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1254 maximum numbers of LUNs, SCSI ID's and target
1256 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1258 The environment variable 'scsidevs' is set to the number of
1259 SCSI devices found during the last scan.
1261 - NETWORK Support (PCI):
1263 Support for Intel 8254x/8257x gigabit chips.
1266 Utility code for direct access to the SPI bus on Intel 8257x.
1267 This does not do anything useful unless you set at least one
1268 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1270 CONFIG_E1000_SPI_GENERIC
1271 Allow generic access to the SPI bus on the Intel 8257x, for
1272 example with the "sspi" command.
1275 Management command for E1000 devices. When used on devices
1276 with SPI support you can reprogram the EEPROM from U-Boot.
1278 CONFIG_E1000_FALLBACK_MAC
1279 default MAC for empty EEPROM after production.
1282 Support for Intel 82557/82559/82559ER chips.
1283 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1284 write routine for first time initialisation.
1287 Support for Digital 2114x chips.
1288 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1289 modem chip initialisation (KS8761/QS6611).
1292 Support for National dp83815 chips.
1295 Support for National dp8382[01] gigabit chips.
1297 - NETWORK Support (other):
1299 CONFIG_DRIVER_AT91EMAC
1300 Support for AT91RM9200 EMAC.
1303 Define this to use reduced MII inteface
1305 CONFIG_DRIVER_AT91EMAC_QUIET
1306 If this defined, the driver is quiet.
1307 The driver doen't show link status messages.
1309 CONFIG_CALXEDA_XGMAC
1310 Support for the Calxeda XGMAC device
1313 Support for SMSC's LAN91C96 chips.
1315 CONFIG_LAN91C96_BASE
1316 Define this to hold the physical address
1317 of the LAN91C96's I/O space
1319 CONFIG_LAN91C96_USE_32_BIT
1320 Define this to enable 32 bit addressing
1323 Support for SMSC's LAN91C111 chip
1325 CONFIG_SMC91111_BASE
1326 Define this to hold the physical address
1327 of the device (I/O space)
1329 CONFIG_SMC_USE_32_BIT
1330 Define this if data bus is 32 bits
1332 CONFIG_SMC_USE_IOFUNCS
1333 Define this to use i/o functions instead of macros
1334 (some hardware wont work with macros)
1336 CONFIG_DRIVER_TI_EMAC
1337 Support for davinci emac
1339 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1340 Define this if you have more then 3 PHYs.
1343 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1345 CONFIG_FTGMAC100_EGIGA
1346 Define this to use GE link update with gigabit PHY.
1347 Define this if FTGMAC100 is connected to gigabit PHY.
1348 If your system has 10/100 PHY only, it might not occur
1349 wrong behavior. Because PHY usually return timeout or
1350 useless data when polling gigabit status and gigabit
1351 control registers. This behavior won't affect the
1352 correctnessof 10/100 link speed update.
1355 Support for SMSC's LAN911x and LAN921x chips
1358 Define this to hold the physical address
1359 of the device (I/O space)
1361 CONFIG_SMC911X_32_BIT
1362 Define this if data bus is 32 bits
1364 CONFIG_SMC911X_16_BIT
1365 Define this if data bus is 16 bits. If your processor
1366 automatically converts one 32 bit word to two 16 bit
1367 words you may also try CONFIG_SMC911X_32_BIT.
1370 Support for Renesas on-chip Ethernet controller
1372 CONFIG_SH_ETHER_USE_PORT
1373 Define the number of ports to be used
1375 CONFIG_SH_ETHER_PHY_ADDR
1376 Define the ETH PHY's address
1378 CONFIG_SH_ETHER_CACHE_WRITEBACK
1379 If this option is set, the driver enables cache flush.
1383 Support TPM devices.
1386 Support for i2c bus TPM devices. Only one device
1387 per system is supported at this time.
1389 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1390 Define the the i2c bus number for the TPM device
1392 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1393 Define the TPM's address on the i2c bus
1395 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1396 Define the burst count bytes upper limit
1398 CONFIG_TPM_ATMEL_TWI
1399 Support for Atmel TWI TPM device. Requires I2C support.
1402 Support for generic parallel port TPM devices. Only one device
1403 per system is supported at this time.
1405 CONFIG_TPM_TIS_BASE_ADDRESS
1406 Base address where the generic TPM device is mapped
1407 to. Contemporary x86 systems usually map it at
1411 Add tpm monitor functions.
1412 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1413 provides monitor access to authorized functions.
1416 Define this to enable the TPM support library which provides
1417 functional interfaces to some TPM commands.
1418 Requires support for a TPM device.
1420 CONFIG_TPM_AUTH_SESSIONS
1421 Define this to enable authorized functions in the TPM library.
1422 Requires CONFIG_TPM and CONFIG_SHA1.
1425 At the moment only the UHCI host controller is
1426 supported (PIP405, MIP405, MPC5200); define
1427 CONFIG_USB_UHCI to enable it.
1428 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1429 and define CONFIG_USB_STORAGE to enable the USB
1432 Supported are USB Keyboards and USB Floppy drives
1434 MPC5200 USB requires additional defines:
1436 for 528 MHz Clock: 0x0001bbbb
1440 for differential drivers: 0x00001000
1441 for single ended drivers: 0x00005000
1442 for differential drivers on PSC3: 0x00000100
1443 for single ended drivers on PSC3: 0x00004100
1444 CONFIG_SYS_USB_EVENT_POLL
1445 May be defined to allow interrupt polling
1446 instead of using asynchronous interrupts
1448 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1449 txfilltuning field in the EHCI controller on reset.
1452 Define the below if you wish to use the USB console.
1453 Once firmware is rebuilt from a serial console issue the
1454 command "setenv stdin usbtty; setenv stdout usbtty" and
1455 attach your USB cable. The Unix command "dmesg" should print
1456 it has found a new device. The environment variable usbtty
1457 can be set to gserial or cdc_acm to enable your device to
1458 appear to a USB host as a Linux gserial device or a
1459 Common Device Class Abstract Control Model serial device.
1460 If you select usbtty = gserial you should be able to enumerate
1462 # modprobe usbserial vendor=0xVendorID product=0xProductID
1463 else if using cdc_acm, simply setting the environment
1464 variable usbtty to be cdc_acm should suffice. The following
1465 might be defined in YourBoardName.h
1468 Define this to build a UDC device
1471 Define this to have a tty type of device available to
1472 talk to the UDC device
1475 Define this to enable the high speed support for usb
1476 device and usbtty. If this feature is enabled, a routine
1477 int is_usbd_high_speed(void)
1478 also needs to be defined by the driver to dynamically poll
1479 whether the enumeration has succeded at high speed or full
1482 CONFIG_SYS_CONSOLE_IS_IN_ENV
1483 Define this if you want stdin, stdout &/or stderr to
1487 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1488 Derive USB clock from external clock "blah"
1489 - CONFIG_SYS_USB_EXTC_CLK 0x02
1491 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1492 Derive USB clock from brgclk
1493 - CONFIG_SYS_USB_BRG_CLK 0x04
1495 If you have a USB-IF assigned VendorID then you may wish to
1496 define your own vendor specific values either in BoardName.h
1497 or directly in usbd_vendor_info.h. If you don't define
1498 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1499 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1500 should pretend to be a Linux device to it's target host.
1502 CONFIG_USBD_MANUFACTURER
1503 Define this string as the name of your company for
1504 - CONFIG_USBD_MANUFACTURER "my company"
1506 CONFIG_USBD_PRODUCT_NAME
1507 Define this string as the name of your product
1508 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1510 CONFIG_USBD_VENDORID
1511 Define this as your assigned Vendor ID from the USB
1512 Implementors Forum. This *must* be a genuine Vendor ID
1513 to avoid polluting the USB namespace.
1514 - CONFIG_USBD_VENDORID 0xFFFF
1516 CONFIG_USBD_PRODUCTID
1517 Define this as the unique Product ID
1519 - CONFIG_USBD_PRODUCTID 0xFFFF
1521 - ULPI Layer Support:
1522 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1523 the generic ULPI layer. The generic layer accesses the ULPI PHY
1524 via the platform viewport, so you need both the genric layer and
1525 the viewport enabled. Currently only Chipidea/ARC based
1526 viewport is supported.
1527 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1528 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1529 If your ULPI phy needs a different reference clock than the
1530 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1531 the appropriate value in Hz.
1534 The MMC controller on the Intel PXA is supported. To
1535 enable this define CONFIG_MMC. The MMC can be
1536 accessed from the boot prompt by mapping the device
1537 to physical memory similar to flash. Command line is
1538 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1539 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1542 Support for Renesas on-chip MMCIF controller
1544 CONFIG_SH_MMCIF_ADDR
1545 Define the base address of MMCIF registers
1548 Define the clock frequency for MMCIF
1551 Enable the generic MMC driver
1553 CONFIG_SUPPORT_EMMC_BOOT
1554 Enable some additional features of the eMMC boot partitions.
1556 CONFIG_SUPPORT_EMMC_RPMB
1557 Enable the commands for reading, writing and programming the
1558 key for the Replay Protection Memory Block partition in eMMC.
1560 - USB Device Firmware Update (DFU) class support:
1562 This enables the USB portion of the DFU USB class
1565 This enables the command "dfu" which is used to have
1566 U-Boot create a DFU class device via USB. This command
1567 requires that the "dfu_alt_info" environment variable be
1568 set and define the alt settings to expose to the host.
1571 This enables support for exposing (e)MMC devices via DFU.
1574 This enables support for exposing NAND devices via DFU.
1577 This enables support for exposing RAM via DFU.
1578 Note: DFU spec refer to non-volatile memory usage, but
1579 allow usages beyond the scope of spec - here RAM usage,
1580 one that would help mostly the developer.
1582 CONFIG_SYS_DFU_DATA_BUF_SIZE
1583 Dfu transfer uses a buffer before writing data to the
1584 raw storage device. Make the size (in bytes) of this buffer
1585 configurable. The size of this buffer is also configurable
1586 through the "dfu_bufsiz" environment variable.
1588 CONFIG_SYS_DFU_MAX_FILE_SIZE
1589 When updating files rather than the raw storage device,
1590 we use a static buffer to copy the file into and then write
1591 the buffer once we've been given the whole file. Define
1592 this to the maximum filesize (in bytes) for the buffer.
1593 Default is 4 MiB if undefined.
1595 DFU_DEFAULT_POLL_TIMEOUT
1596 Poll timeout [ms], is the timeout a device can send to the
1597 host. The host must wait for this timeout before sending
1598 a subsequent DFU_GET_STATUS request to the device.
1600 DFU_MANIFEST_POLL_TIMEOUT
1601 Poll timeout [ms], which the device sends to the host when
1602 entering dfuMANIFEST state. Host waits this timeout, before
1603 sending again an USB request to the device.
1605 - USB Device Android Fastboot support:
1607 This enables the command "fastboot" which enables the Android
1608 fastboot mode for the platform's USB device. Fastboot is a USB
1609 protocol for downloading images, flashing and device control
1610 used on Android devices.
1611 See doc/README.android-fastboot for more information.
1613 CONFIG_ANDROID_BOOT_IMAGE
1614 This enables support for booting images which use the Android
1615 image format header.
1617 CONFIG_USB_FASTBOOT_BUF_ADDR
1618 The fastboot protocol requires a large memory buffer for
1619 downloads. Define this to the starting RAM address to use for
1622 CONFIG_USB_FASTBOOT_BUF_SIZE
1623 The fastboot protocol requires a large memory buffer for
1624 downloads. This buffer should be as large as possible for a
1625 platform. Define this to the size available RAM for fastboot.
1627 - Journaling Flash filesystem support:
1628 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1629 CONFIG_JFFS2_NAND_DEV
1630 Define these for a default partition on a NAND device
1632 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1633 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1634 Define these for a default partition on a NOR device
1636 CONFIG_SYS_JFFS_CUSTOM_PART
1637 Define this to create an own partition. You have to provide a
1638 function struct part_info* jffs2_part_info(int part_num)
1640 If you define only one JFFS2 partition you may also want to
1641 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1642 to disable the command chpart. This is the default when you
1643 have not defined a custom partition
1645 - FAT(File Allocation Table) filesystem write function support:
1648 Define this to enable support for saving memory data as a
1649 file in FAT formatted partition.
1651 This will also enable the command "fatwrite" enabling the
1652 user to write files to FAT.
1654 CBFS (Coreboot Filesystem) support
1657 Define this to enable support for reading from a Coreboot
1658 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1661 - FAT(File Allocation Table) filesystem cluster size:
1662 CONFIG_FS_FAT_MAX_CLUSTSIZE
1664 Define the max cluster size for fat operations else
1665 a default value of 65536 will be defined.
1670 Define this to enable standard (PC-Style) keyboard
1674 Standard PC keyboard driver with US (is default) and
1675 GERMAN key layout (switch via environment 'keymap=de') support.
1676 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1677 for cfb_console. Supports cursor blinking.
1680 Enables a Chrome OS keyboard using the CROS_EC interface.
1681 This uses CROS_EC to communicate with a second microcontroller
1682 which provides key scans on request.
1687 Define this to enable video support (for output to
1690 CONFIG_VIDEO_CT69000
1692 Enable Chips & Technologies 69000 Video chip
1694 CONFIG_VIDEO_SMI_LYNXEM
1695 Enable Silicon Motion SMI 712/710/810 Video chip. The
1696 video output is selected via environment 'videoout'
1697 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1700 For the CT69000 and SMI_LYNXEM drivers, videomode is
1701 selected via environment 'videomode'. Two different ways
1703 - "videomode=num" 'num' is a standard LiLo mode numbers.
1704 Following standard modes are supported (* is default):
1706 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1707 -------------+---------------------------------------------
1708 8 bits | 0x301* 0x303 0x305 0x161 0x307
1709 15 bits | 0x310 0x313 0x316 0x162 0x319
1710 16 bits | 0x311 0x314 0x317 0x163 0x31A
1711 24 bits | 0x312 0x315 0x318 ? 0x31B
1712 -------------+---------------------------------------------
1713 (i.e. setenv videomode 317; saveenv; reset;)
1715 - "videomode=bootargs" all the video parameters are parsed
1716 from the bootargs. (See drivers/video/videomodes.c)
1719 CONFIG_VIDEO_SED13806
1720 Enable Epson SED13806 driver. This driver supports 8bpp
1721 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1722 or CONFIG_VIDEO_SED13806_16BPP
1725 Enable the Freescale DIU video driver. Reference boards for
1726 SOCs that have a DIU should define this macro to enable DIU
1727 support, and should also define these other macros:
1733 CONFIG_VIDEO_SW_CURSOR
1734 CONFIG_VGA_AS_SINGLE_DEVICE
1736 CONFIG_VIDEO_BMP_LOGO
1738 The DIU driver will look for the 'video-mode' environment
1739 variable, and if defined, enable the DIU as a console during
1740 boot. See the documentation file README.video for a
1741 description of this variable.
1745 Enable the VGA video / BIOS for x86. The alternative if you
1746 are using coreboot is to use the coreboot frame buffer
1753 Define this to enable a custom keyboard support.
1754 This simply calls drv_keyboard_init() which must be
1755 defined in your board-specific files.
1756 The only board using this so far is RBC823.
1758 - LCD Support: CONFIG_LCD
1760 Define this to enable LCD support (for output to LCD
1761 display); also select one of the supported displays
1762 by defining one of these:
1766 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1768 CONFIG_NEC_NL6448AC33:
1770 NEC NL6448AC33-18. Active, color, single scan.
1772 CONFIG_NEC_NL6448BC20
1774 NEC NL6448BC20-08. 6.5", 640x480.
1775 Active, color, single scan.
1777 CONFIG_NEC_NL6448BC33_54
1779 NEC NL6448BC33-54. 10.4", 640x480.
1780 Active, color, single scan.
1784 Sharp 320x240. Active, color, single scan.
1785 It isn't 16x9, and I am not sure what it is.
1787 CONFIG_SHARP_LQ64D341
1789 Sharp LQ64D341 display, 640x480.
1790 Active, color, single scan.
1794 HLD1045 display, 640x480.
1795 Active, color, single scan.
1799 Optrex CBL50840-2 NF-FW 99 22 M5
1801 Hitachi LMG6912RPFC-00T
1805 320x240. Black & white.
1807 Normally display is black on white background; define
1808 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1810 CONFIG_LCD_ALIGNMENT
1812 Normally the LCD is page-aligned (tyically 4KB). If this is
1813 defined then the LCD will be aligned to this value instead.
1814 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1815 here, since it is cheaper to change data cache settings on
1816 a per-section basis.
1818 CONFIG_CONSOLE_SCROLL_LINES
1820 When the console need to be scrolled, this is the number of
1821 lines to scroll by. It defaults to 1. Increasing this makes
1822 the console jump but can help speed up operation when scrolling
1827 Support drawing of RLE8-compressed bitmaps on the LCD.
1831 Enables an 'i2c edid' command which can read EDID
1832 information over I2C from an attached LCD display.
1834 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1836 If this option is set, the environment is checked for
1837 a variable "splashimage". If found, the usual display
1838 of logo, copyright and system information on the LCD
1839 is suppressed and the BMP image at the address
1840 specified in "splashimage" is loaded instead. The
1841 console is redirected to the "nulldev", too. This
1842 allows for a "silent" boot where a splash screen is
1843 loaded very quickly after power-on.
1845 CONFIG_SPLASHIMAGE_GUARD
1847 If this option is set, then U-Boot will prevent the environment
1848 variable "splashimage" from being set to a problematic address
1849 (see README.displaying-bmps).
1850 This option is useful for targets where, due to alignment
1851 restrictions, an improperly aligned BMP image will cause a data
1852 abort. If you think you will not have problems with unaligned
1853 accesses (for example because your toolchain prevents them)
1854 there is no need to set this option.
1856 CONFIG_SPLASH_SCREEN_ALIGN
1858 If this option is set the splash image can be freely positioned
1859 on the screen. Environment variable "splashpos" specifies the
1860 position as "x,y". If a positive number is given it is used as
1861 number of pixel from left/top. If a negative number is given it
1862 is used as number of pixel from right/bottom. You can also
1863 specify 'm' for centering the image.
1866 setenv splashpos m,m
1867 => image at center of screen
1869 setenv splashpos 30,20
1870 => image at x = 30 and y = 20
1872 setenv splashpos -10,m
1873 => vertically centered image
1874 at x = dspWidth - bmpWidth - 9
1876 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1878 If this option is set, additionally to standard BMP
1879 images, gzipped BMP images can be displayed via the
1880 splashscreen support or the bmp command.
1882 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1884 If this option is set, 8-bit RLE compressed BMP images
1885 can be displayed via the splashscreen support or the
1888 - Do compresssing for memory range:
1891 If this option is set, it would use zlib deflate method
1892 to compress the specified memory at its best effort.
1894 - Compression support:
1897 Enabled by default to support gzip compressed images.
1901 If this option is set, support for bzip2 compressed
1902 images is included. If not, only uncompressed and gzip
1903 compressed images are supported.
1905 NOTE: the bzip2 algorithm requires a lot of RAM, so
1906 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1911 If this option is set, support for lzma compressed
1914 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1915 requires an amount of dynamic memory that is given by the
1918 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1920 Where lc and lp stand for, respectively, Literal context bits
1921 and Literal pos bits.
1923 This value is upper-bounded by 14MB in the worst case. Anyway,
1924 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1925 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1926 a very small buffer.
1928 Use the lzmainfo tool to determinate the lc and lp values and
1929 then calculate the amount of needed dynamic memory (ensuring
1930 the appropriate CONFIG_SYS_MALLOC_LEN value).
1934 If this option is set, support for LZO compressed images
1940 The address of PHY on MII bus.
1942 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1944 The clock frequency of the MII bus
1948 If this option is set, support for speed/duplex
1949 detection of gigabit PHY is included.
1951 CONFIG_PHY_RESET_DELAY
1953 Some PHY like Intel LXT971A need extra delay after
1954 reset before any MII register access is possible.
1955 For such PHY, set this option to the usec delay
1956 required. (minimum 300usec for LXT971A)
1958 CONFIG_PHY_CMD_DELAY (ppc4xx)
1960 Some PHY like Intel LXT971A need extra delay after
1961 command issued before MII status register can be read
1971 Define a default value for Ethernet address to use
1972 for the respective Ethernet interface, in case this
1973 is not determined automatically.
1978 Define a default value for the IP address to use for
1979 the default Ethernet interface, in case this is not
1980 determined through e.g. bootp.
1981 (Environment variable "ipaddr")
1983 - Server IP address:
1986 Defines a default value for the IP address of a TFTP
1987 server to contact when using the "tftboot" command.
1988 (Environment variable "serverip")
1990 CONFIG_KEEP_SERVERADDR
1992 Keeps the server's MAC address, in the env 'serveraddr'
1993 for passing to bootargs (like Linux's netconsole option)
1995 - Gateway IP address:
1998 Defines a default value for the IP address of the
1999 default router where packets to other networks are
2001 (Environment variable "gatewayip")
2006 Defines a default value for the subnet mask (or
2007 routing prefix) which is used to determine if an IP
2008 address belongs to the local subnet or needs to be
2009 forwarded through a router.
2010 (Environment variable "netmask")
2012 - Multicast TFTP Mode:
2015 Defines whether you want to support multicast TFTP as per
2016 rfc-2090; for example to work with atftp. Lets lots of targets
2017 tftp down the same boot image concurrently. Note: the Ethernet
2018 driver in use must provide a function: mcast() to join/leave a
2021 - BOOTP Recovery Mode:
2022 CONFIG_BOOTP_RANDOM_DELAY
2024 If you have many targets in a network that try to
2025 boot using BOOTP, you may want to avoid that all
2026 systems send out BOOTP requests at precisely the same
2027 moment (which would happen for instance at recovery
2028 from a power failure, when all systems will try to
2029 boot, thus flooding the BOOTP server. Defining
2030 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2031 inserted before sending out BOOTP requests. The
2032 following delays are inserted then:
2034 1st BOOTP request: delay 0 ... 1 sec
2035 2nd BOOTP request: delay 0 ... 2 sec
2036 3rd BOOTP request: delay 0 ... 4 sec
2038 BOOTP requests: delay 0 ... 8 sec
2040 CONFIG_BOOTP_ID_CACHE_SIZE
2042 BOOTP packets are uniquely identified using a 32-bit ID. The
2043 server will copy the ID from client requests to responses and
2044 U-Boot will use this to determine if it is the destination of
2045 an incoming response. Some servers will check that addresses
2046 aren't in use before handing them out (usually using an ARP
2047 ping) and therefore take up to a few hundred milliseconds to
2048 respond. Network congestion may also influence the time it
2049 takes for a response to make it back to the client. If that
2050 time is too long, U-Boot will retransmit requests. In order
2051 to allow earlier responses to still be accepted after these
2052 retransmissions, U-Boot's BOOTP client keeps a small cache of
2053 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2054 cache. The default is to keep IDs for up to four outstanding
2055 requests. Increasing this will allow U-Boot to accept offers
2056 from a BOOTP client in networks with unusually high latency.
2058 - DHCP Advanced Options:
2059 You can fine tune the DHCP functionality by defining
2060 CONFIG_BOOTP_* symbols:
2062 CONFIG_BOOTP_SUBNETMASK
2063 CONFIG_BOOTP_GATEWAY
2064 CONFIG_BOOTP_HOSTNAME
2065 CONFIG_BOOTP_NISDOMAIN
2066 CONFIG_BOOTP_BOOTPATH
2067 CONFIG_BOOTP_BOOTFILESIZE
2070 CONFIG_BOOTP_SEND_HOSTNAME
2071 CONFIG_BOOTP_NTPSERVER
2072 CONFIG_BOOTP_TIMEOFFSET
2073 CONFIG_BOOTP_VENDOREX
2074 CONFIG_BOOTP_MAY_FAIL
2076 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2077 environment variable, not the BOOTP server.
2079 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2080 after the configured retry count, the call will fail
2081 instead of starting over. This can be used to fail over
2082 to Link-local IP address configuration if the DHCP server
2085 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2086 serverip from a DHCP server, it is possible that more
2087 than one DNS serverip is offered to the client.
2088 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2089 serverip will be stored in the additional environment
2090 variable "dnsip2". The first DNS serverip is always
2091 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2094 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2095 to do a dynamic update of a DNS server. To do this, they
2096 need the hostname of the DHCP requester.
2097 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2098 of the "hostname" environment variable is passed as
2099 option 12 to the DHCP server.
2101 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2103 A 32bit value in microseconds for a delay between
2104 receiving a "DHCP Offer" and sending the "DHCP Request".
2105 This fixes a problem with certain DHCP servers that don't
2106 respond 100% of the time to a "DHCP request". E.g. On an
2107 AT91RM9200 processor running at 180MHz, this delay needed
2108 to be *at least* 15,000 usec before a Windows Server 2003
2109 DHCP server would reply 100% of the time. I recommend at
2110 least 50,000 usec to be safe. The alternative is to hope
2111 that one of the retries will be successful but note that
2112 the DHCP timeout and retry process takes a longer than
2115 - Link-local IP address negotiation:
2116 Negotiate with other link-local clients on the local network
2117 for an address that doesn't require explicit configuration.
2118 This is especially useful if a DHCP server cannot be guaranteed
2119 to exist in all environments that the device must operate.
2121 See doc/README.link-local for more information.
2124 CONFIG_CDP_DEVICE_ID
2126 The device id used in CDP trigger frames.
2128 CONFIG_CDP_DEVICE_ID_PREFIX
2130 A two character string which is prefixed to the MAC address
2135 A printf format string which contains the ascii name of
2136 the port. Normally is set to "eth%d" which sets
2137 eth0 for the first Ethernet, eth1 for the second etc.
2139 CONFIG_CDP_CAPABILITIES
2141 A 32bit integer which indicates the device capabilities;
2142 0x00000010 for a normal host which does not forwards.
2146 An ascii string containing the version of the software.
2150 An ascii string containing the name of the platform.
2154 A 32bit integer sent on the trigger.
2156 CONFIG_CDP_POWER_CONSUMPTION
2158 A 16bit integer containing the power consumption of the
2159 device in .1 of milliwatts.
2161 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2163 A byte containing the id of the VLAN.
2165 - Status LED: CONFIG_STATUS_LED
2167 Several configurations allow to display the current
2168 status using a LED. For instance, the LED will blink
2169 fast while running U-Boot code, stop blinking as
2170 soon as a reply to a BOOTP request was received, and
2171 start blinking slow once the Linux kernel is running
2172 (supported by a status LED driver in the Linux
2173 kernel). Defining CONFIG_STATUS_LED enables this
2179 The status LED can be connected to a GPIO pin.
2180 In such cases, the gpio_led driver can be used as a
2181 status LED backend implementation. Define CONFIG_GPIO_LED
2182 to include the gpio_led driver in the U-Boot binary.
2184 CONFIG_GPIO_LED_INVERTED_TABLE
2185 Some GPIO connected LEDs may have inverted polarity in which
2186 case the GPIO high value corresponds to LED off state and
2187 GPIO low value corresponds to LED on state.
2188 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2189 with a list of GPIO LEDs that have inverted polarity.
2191 - CAN Support: CONFIG_CAN_DRIVER
2193 Defining CONFIG_CAN_DRIVER enables CAN driver support
2194 on those systems that support this (optional)
2195 feature, like the TQM8xxL modules.
2197 - I2C Support: CONFIG_SYS_I2C
2199 This enable the NEW i2c subsystem, and will allow you to use
2200 i2c commands at the u-boot command line (as long as you set
2201 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2202 based realtime clock chips or other i2c devices. See
2203 common/cmd_i2c.c for a description of the command line
2206 ported i2c driver to the new framework:
2207 - drivers/i2c/soft_i2c.c:
2208 - activate first bus with CONFIG_SYS_I2C_SOFT define
2209 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2210 for defining speed and slave address
2211 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2212 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2213 for defining speed and slave address
2214 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2215 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2216 for defining speed and slave address
2217 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2218 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2219 for defining speed and slave address
2221 - drivers/i2c/fsl_i2c.c:
2222 - activate i2c driver with CONFIG_SYS_I2C_FSL
2223 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2224 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2225 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2227 - If your board supports a second fsl i2c bus, define
2228 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2229 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2230 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2233 - drivers/i2c/tegra_i2c.c:
2234 - activate this driver with CONFIG_SYS_I2C_TEGRA
2235 - This driver adds 4 i2c buses with a fix speed from
2236 100000 and the slave addr 0!
2238 - drivers/i2c/ppc4xx_i2c.c
2239 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2240 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2241 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2243 - drivers/i2c/i2c_mxc.c
2244 - activate this driver with CONFIG_SYS_I2C_MXC
2245 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2246 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2247 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2248 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2249 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2250 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2251 If thoses defines are not set, default value is 100000
2252 for speed, and 0 for slave.
2254 - drivers/i2c/rcar_i2c.c:
2255 - activate this driver with CONFIG_SYS_I2C_RCAR
2256 - This driver adds 4 i2c buses
2258 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2259 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2260 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2261 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2262 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2263 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2264 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2265 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2266 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2268 - drivers/i2c/sh_i2c.c:
2269 - activate this driver with CONFIG_SYS_I2C_SH
2270 - This driver adds from 2 to 5 i2c buses
2272 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2273 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2274 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2275 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2276 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2277 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2278 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2279 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2280 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2281 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2282 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2283 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2284 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2286 - drivers/i2c/omap24xx_i2c.c
2287 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2288 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2289 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2290 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2291 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2292 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2293 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2294 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2295 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2296 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2297 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2299 - drivers/i2c/zynq_i2c.c
2300 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2301 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2302 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2304 - drivers/i2c/s3c24x0_i2c.c:
2305 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2306 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2307 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2308 with a fix speed from 100000 and the slave addr 0!
2310 - drivers/i2c/ihs_i2c.c
2311 - activate this driver with CONFIG_SYS_I2C_IHS
2312 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2313 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2314 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2315 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2316 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2317 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2318 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2319 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2320 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2321 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2322 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2323 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2327 CONFIG_SYS_NUM_I2C_BUSES
2328 Hold the number of i2c busses you want to use. If you
2329 don't use/have i2c muxes on your i2c bus, this
2330 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2333 CONFIG_SYS_I2C_DIRECT_BUS
2334 define this, if you don't use i2c muxes on your hardware.
2335 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2338 CONFIG_SYS_I2C_MAX_HOPS
2339 define how many muxes are maximal consecutively connected
2340 on one i2c bus. If you not use i2c muxes, omit this
2343 CONFIG_SYS_I2C_BUSES
2344 hold a list of busses you want to use, only used if
2345 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2346 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2347 CONFIG_SYS_NUM_I2C_BUSES = 9:
2349 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2350 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2351 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2352 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2353 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2354 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2355 {1, {I2C_NULL_HOP}}, \
2356 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2357 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2361 bus 0 on adapter 0 without a mux
2362 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2363 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2364 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2365 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2366 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2367 bus 6 on adapter 1 without a mux
2368 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2369 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2371 If you do not have i2c muxes on your board, omit this define.
2373 - Legacy I2C Support: CONFIG_HARD_I2C
2375 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2376 provides the following compelling advantages:
2378 - more than one i2c adapter is usable
2379 - approved multibus support
2380 - better i2c mux support
2382 ** Please consider updating your I2C driver now. **
2384 These enable legacy I2C serial bus commands. Defining
2385 CONFIG_HARD_I2C will include the appropriate I2C driver
2386 for the selected CPU.
2388 This will allow you to use i2c commands at the u-boot
2389 command line (as long as you set CONFIG_CMD_I2C in
2390 CONFIG_COMMANDS) and communicate with i2c based realtime
2391 clock chips. See common/cmd_i2c.c for a description of the
2392 command line interface.
2394 CONFIG_HARD_I2C selects a hardware I2C controller.
2396 There are several other quantities that must also be
2397 defined when you define CONFIG_HARD_I2C.
2399 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2400 to be the frequency (in Hz) at which you wish your i2c bus
2401 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2402 the CPU's i2c node address).
2404 Now, the u-boot i2c code for the mpc8xx
2405 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2406 and so its address should therefore be cleared to 0 (See,
2407 eg, MPC823e User's Manual p.16-473). So, set
2408 CONFIG_SYS_I2C_SLAVE to 0.
2410 CONFIG_SYS_I2C_INIT_MPC5XXX
2412 When a board is reset during an i2c bus transfer
2413 chips might think that the current transfer is still
2414 in progress. Reset the slave devices by sending start
2415 commands until the slave device responds.
2417 That's all that's required for CONFIG_HARD_I2C.
2419 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2420 then the following macros need to be defined (examples are
2421 from include/configs/lwmon.h):
2425 (Optional). Any commands necessary to enable the I2C
2426 controller or configure ports.
2428 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2432 (Only for MPC8260 CPU). The I/O port to use (the code
2433 assumes both bits are on the same port). Valid values
2434 are 0..3 for ports A..D.
2438 The code necessary to make the I2C data line active
2439 (driven). If the data line is open collector, this
2442 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2446 The code necessary to make the I2C data line tri-stated
2447 (inactive). If the data line is open collector, this
2450 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2454 Code that returns true if the I2C data line is high,
2457 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2461 If <bit> is true, sets the I2C data line high. If it
2462 is false, it clears it (low).
2464 eg: #define I2C_SDA(bit) \
2465 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2466 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2470 If <bit> is true, sets the I2C clock line high. If it
2471 is false, it clears it (low).
2473 eg: #define I2C_SCL(bit) \
2474 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2475 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2479 This delay is invoked four times per clock cycle so this
2480 controls the rate of data transfer. The data rate thus
2481 is 1 / (I2C_DELAY * 4). Often defined to be something
2484 #define I2C_DELAY udelay(2)
2486 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2488 If your arch supports the generic GPIO framework (asm/gpio.h),
2489 then you may alternatively define the two GPIOs that are to be
2490 used as SCL / SDA. Any of the previous I2C_xxx macros will
2491 have GPIO-based defaults assigned to them as appropriate.
2493 You should define these to the GPIO value as given directly to
2494 the generic GPIO functions.
2496 CONFIG_SYS_I2C_INIT_BOARD
2498 When a board is reset during an i2c bus transfer
2499 chips might think that the current transfer is still
2500 in progress. On some boards it is possible to access
2501 the i2c SCLK line directly, either by using the
2502 processor pin as a GPIO or by having a second pin
2503 connected to the bus. If this option is defined a
2504 custom i2c_init_board() routine in boards/xxx/board.c
2505 is run early in the boot sequence.
2507 CONFIG_SYS_I2C_BOARD_LATE_INIT
2509 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2510 defined a custom i2c_board_late_init() routine in
2511 boards/xxx/board.c is run AFTER the operations in i2c_init()
2512 is completed. This callpoint can be used to unreset i2c bus
2513 using CPU i2c controller register accesses for CPUs whose i2c
2514 controller provide such a method. It is called at the end of
2515 i2c_init() to allow i2c_init operations to setup the i2c bus
2516 controller on the CPU (e.g. setting bus speed & slave address).
2518 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2520 This option enables configuration of bi_iic_fast[] flags
2521 in u-boot bd_info structure based on u-boot environment
2522 variable "i2cfast". (see also i2cfast)
2524 CONFIG_I2C_MULTI_BUS
2526 This option allows the use of multiple I2C buses, each of which
2527 must have a controller. At any point in time, only one bus is
2528 active. To switch to a different bus, use the 'i2c dev' command.
2529 Note that bus numbering is zero-based.
2531 CONFIG_SYS_I2C_NOPROBES
2533 This option specifies a list of I2C devices that will be skipped
2534 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2535 is set, specify a list of bus-device pairs. Otherwise, specify
2536 a 1D array of device addresses
2539 #undef CONFIG_I2C_MULTI_BUS
2540 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2542 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2544 #define CONFIG_I2C_MULTI_BUS
2545 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2547 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2549 CONFIG_SYS_SPD_BUS_NUM
2551 If defined, then this indicates the I2C bus number for DDR SPD.
2552 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2554 CONFIG_SYS_RTC_BUS_NUM
2556 If defined, then this indicates the I2C bus number for the RTC.
2557 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2559 CONFIG_SYS_DTT_BUS_NUM
2561 If defined, then this indicates the I2C bus number for the DTT.
2562 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2564 CONFIG_SYS_I2C_DTT_ADDR:
2566 If defined, specifies the I2C address of the DTT device.
2567 If not defined, then U-Boot uses predefined value for
2568 specified DTT device.
2570 CONFIG_SOFT_I2C_READ_REPEATED_START
2572 defining this will force the i2c_read() function in
2573 the soft_i2c driver to perform an I2C repeated start
2574 between writing the address pointer and reading the
2575 data. If this define is omitted the default behaviour
2576 of doing a stop-start sequence will be used. Most I2C
2577 devices can use either method, but some require one or
2580 - SPI Support: CONFIG_SPI
2582 Enables SPI driver (so far only tested with
2583 SPI EEPROM, also an instance works with Crystal A/D and
2584 D/As on the SACSng board)
2588 Enables the driver for SPI controller on SuperH. Currently
2589 only SH7757 is supported.
2593 Enables extended (16-bit) SPI EEPROM addressing.
2594 (symmetrical to CONFIG_I2C_X)
2598 Enables a software (bit-bang) SPI driver rather than
2599 using hardware support. This is a general purpose
2600 driver that only requires three general I/O port pins
2601 (two outputs, one input) to function. If this is
2602 defined, the board configuration must define several
2603 SPI configuration items (port pins to use, etc). For
2604 an example, see include/configs/sacsng.h.
2608 Enables a hardware SPI driver for general-purpose reads
2609 and writes. As with CONFIG_SOFT_SPI, the board configuration
2610 must define a list of chip-select function pointers.
2611 Currently supported on some MPC8xxx processors. For an
2612 example, see include/configs/mpc8349emds.h.
2616 Enables the driver for the SPI controllers on i.MX and MXC
2617 SoCs. Currently i.MX31/35/51 are supported.
2619 CONFIG_SYS_SPI_MXC_WAIT
2620 Timeout for waiting until spi transfer completed.
2621 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2623 - FPGA Support: CONFIG_FPGA
2625 Enables FPGA subsystem.
2627 CONFIG_FPGA_<vendor>
2629 Enables support for specific chip vendors.
2632 CONFIG_FPGA_<family>
2634 Enables support for FPGA family.
2635 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2639 Specify the number of FPGA devices to support.
2641 CONFIG_CMD_FPGA_LOADMK
2643 Enable support for fpga loadmk command
2645 CONFIG_CMD_FPGA_LOADP
2647 Enable support for fpga loadp command - load partial bitstream
2649 CONFIG_CMD_FPGA_LOADBP
2651 Enable support for fpga loadbp command - load partial bitstream
2654 CONFIG_SYS_FPGA_PROG_FEEDBACK
2656 Enable printing of hash marks during FPGA configuration.
2658 CONFIG_SYS_FPGA_CHECK_BUSY
2660 Enable checks on FPGA configuration interface busy
2661 status by the configuration function. This option
2662 will require a board or device specific function to
2667 If defined, a function that provides delays in the FPGA
2668 configuration driver.
2670 CONFIG_SYS_FPGA_CHECK_CTRLC
2671 Allow Control-C to interrupt FPGA configuration
2673 CONFIG_SYS_FPGA_CHECK_ERROR
2675 Check for configuration errors during FPGA bitfile
2676 loading. For example, abort during Virtex II
2677 configuration if the INIT_B line goes low (which
2678 indicated a CRC error).
2680 CONFIG_SYS_FPGA_WAIT_INIT
2682 Maximum time to wait for the INIT_B line to deassert
2683 after PROB_B has been deasserted during a Virtex II
2684 FPGA configuration sequence. The default time is 500
2687 CONFIG_SYS_FPGA_WAIT_BUSY
2689 Maximum time to wait for BUSY to deassert during
2690 Virtex II FPGA configuration. The default is 5 ms.
2692 CONFIG_SYS_FPGA_WAIT_CONFIG
2694 Time to wait after FPGA configuration. The default is
2697 - Configuration Management:
2700 If defined, this string will be added to the U-Boot
2701 version information (U_BOOT_VERSION)
2703 - Vendor Parameter Protection:
2705 U-Boot considers the values of the environment
2706 variables "serial#" (Board Serial Number) and
2707 "ethaddr" (Ethernet Address) to be parameters that
2708 are set once by the board vendor / manufacturer, and
2709 protects these variables from casual modification by
2710 the user. Once set, these variables are read-only,
2711 and write or delete attempts are rejected. You can
2712 change this behaviour:
2714 If CONFIG_ENV_OVERWRITE is #defined in your config
2715 file, the write protection for vendor parameters is
2716 completely disabled. Anybody can change or delete
2719 Alternatively, if you #define _both_ CONFIG_ETHADDR
2720 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2721 Ethernet address is installed in the environment,
2722 which can be changed exactly ONCE by the user. [The
2723 serial# is unaffected by this, i. e. it remains
2726 The same can be accomplished in a more flexible way
2727 for any variable by configuring the type of access
2728 to allow for those variables in the ".flags" variable
2729 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2734 Define this variable to enable the reservation of
2735 "protected RAM", i. e. RAM which is not overwritten
2736 by U-Boot. Define CONFIG_PRAM to hold the number of
2737 kB you want to reserve for pRAM. You can overwrite
2738 this default value by defining an environment
2739 variable "pram" to the number of kB you want to
2740 reserve. Note that the board info structure will
2741 still show the full amount of RAM. If pRAM is
2742 reserved, a new environment variable "mem" will
2743 automatically be defined to hold the amount of
2744 remaining RAM in a form that can be passed as boot
2745 argument to Linux, for instance like that:
2747 setenv bootargs ... mem=\${mem}
2750 This way you can tell Linux not to use this memory,
2751 either, which results in a memory region that will
2752 not be affected by reboots.
2754 *WARNING* If your board configuration uses automatic
2755 detection of the RAM size, you must make sure that
2756 this memory test is non-destructive. So far, the
2757 following board configurations are known to be
2760 IVMS8, IVML24, SPD8xx, TQM8xxL,
2761 HERMES, IP860, RPXlite, LWMON,
2764 - Access to physical memory region (> 4GB)
2765 Some basic support is provided for operations on memory not
2766 normally accessible to U-Boot - e.g. some architectures
2767 support access to more than 4GB of memory on 32-bit
2768 machines using physical address extension or similar.
2769 Define CONFIG_PHYSMEM to access this basic support, which
2770 currently only supports clearing the memory.
2775 Define this variable to stop the system in case of a
2776 fatal error, so that you have to reset it manually.
2777 This is probably NOT a good idea for an embedded
2778 system where you want the system to reboot
2779 automatically as fast as possible, but it may be
2780 useful during development since you can try to debug
2781 the conditions that lead to the situation.
2783 CONFIG_NET_RETRY_COUNT
2785 This variable defines the number of retries for
2786 network operations like ARP, RARP, TFTP, or BOOTP
2787 before giving up the operation. If not defined, a
2788 default value of 5 is used.
2792 Timeout waiting for an ARP reply in milliseconds.
2796 Timeout in milliseconds used in NFS protocol.
2797 If you encounter "ERROR: Cannot umount" in nfs command,
2798 try longer timeout such as
2799 #define CONFIG_NFS_TIMEOUT 10000UL
2801 - Command Interpreter:
2802 CONFIG_AUTO_COMPLETE
2804 Enable auto completion of commands using TAB.
2806 Note that this feature has NOT been implemented yet
2807 for the "hush" shell.
2810 CONFIG_SYS_HUSH_PARSER
2812 Define this variable to enable the "hush" shell (from
2813 Busybox) as command line interpreter, thus enabling
2814 powerful command line syntax like
2815 if...then...else...fi conditionals or `&&' and '||'
2816 constructs ("shell scripts").
2818 If undefined, you get the old, much simpler behaviour
2819 with a somewhat smaller memory footprint.
2822 CONFIG_SYS_PROMPT_HUSH_PS2
2824 This defines the secondary prompt string, which is
2825 printed when the command interpreter needs more input
2826 to complete a command. Usually "> ".
2830 In the current implementation, the local variables
2831 space and global environment variables space are
2832 separated. Local variables are those you define by
2833 simply typing `name=value'. To access a local
2834 variable later on, you have write `$name' or
2835 `${name}'; to execute the contents of a variable
2836 directly type `$name' at the command prompt.
2838 Global environment variables are those you use
2839 setenv/printenv to work with. To run a command stored
2840 in such a variable, you need to use the run command,
2841 and you must not use the '$' sign to access them.
2843 To store commands and special characters in a
2844 variable, please use double quotation marks
2845 surrounding the whole text of the variable, instead
2846 of the backslashes before semicolons and special
2849 - Commandline Editing and History:
2850 CONFIG_CMDLINE_EDITING
2852 Enable editing and History functions for interactive
2853 commandline input operations
2855 - Default Environment:
2856 CONFIG_EXTRA_ENV_SETTINGS
2858 Define this to contain any number of null terminated
2859 strings (variable = value pairs) that will be part of
2860 the default environment compiled into the boot image.
2862 For example, place something like this in your
2863 board's config file:
2865 #define CONFIG_EXTRA_ENV_SETTINGS \
2869 Warning: This method is based on knowledge about the
2870 internal format how the environment is stored by the
2871 U-Boot code. This is NOT an official, exported
2872 interface! Although it is unlikely that this format
2873 will change soon, there is no guarantee either.
2874 You better know what you are doing here.
2876 Note: overly (ab)use of the default environment is
2877 discouraged. Make sure to check other ways to preset
2878 the environment like the "source" command or the
2881 CONFIG_ENV_VARS_UBOOT_CONFIG
2883 Define this in order to add variables describing the
2884 U-Boot build configuration to the default environment.
2885 These will be named arch, cpu, board, vendor, and soc.
2887 Enabling this option will cause the following to be defined:
2895 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2897 Define this in order to add variables describing certain
2898 run-time determined information about the hardware to the
2899 environment. These will be named board_name, board_rev.
2901 CONFIG_DELAY_ENVIRONMENT
2903 Normally the environment is loaded when the board is
2904 intialised so that it is available to U-Boot. This inhibits
2905 that so that the environment is not available until
2906 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2907 this is instead controlled by the value of
2908 /config/load-environment.
2910 - DataFlash Support:
2911 CONFIG_HAS_DATAFLASH
2913 Defining this option enables DataFlash features and
2914 allows to read/write in Dataflash via the standard
2917 - Serial Flash support
2920 Defining this option enables SPI flash commands
2921 'sf probe/read/write/erase/update'.
2923 Usage requires an initial 'probe' to define the serial
2924 flash parameters, followed by read/write/erase/update
2927 The following defaults may be provided by the platform
2928 to handle the common case when only a single serial
2929 flash is present on the system.
2931 CONFIG_SF_DEFAULT_BUS Bus identifier
2932 CONFIG_SF_DEFAULT_CS Chip-select
2933 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2934 CONFIG_SF_DEFAULT_SPEED in Hz
2938 Define this option to include a destructive SPI flash
2941 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2943 Define this option to use the Bank addr/Extended addr
2944 support on SPI flashes which has size > 16Mbytes.
2946 CONFIG_SF_DUAL_FLASH Dual flash memories
2948 Define this option to use dual flash support where two flash
2949 memories can be connected with a given cs line.
2950 currently Xilinx Zynq qspi support these type of connections.
2952 - SystemACE Support:
2955 Adding this option adds support for Xilinx SystemACE
2956 chips attached via some sort of local bus. The address
2957 of the chip must also be defined in the
2958 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2960 #define CONFIG_SYSTEMACE
2961 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2963 When SystemACE support is added, the "ace" device type
2964 becomes available to the fat commands, i.e. fatls.
2966 - TFTP Fixed UDP Port:
2969 If this is defined, the environment variable tftpsrcp
2970 is used to supply the TFTP UDP source port value.
2971 If tftpsrcp isn't defined, the normal pseudo-random port
2972 number generator is used.
2974 Also, the environment variable tftpdstp is used to supply
2975 the TFTP UDP destination port value. If tftpdstp isn't
2976 defined, the normal port 69 is used.
2978 The purpose for tftpsrcp is to allow a TFTP server to
2979 blindly start the TFTP transfer using the pre-configured
2980 target IP address and UDP port. This has the effect of
2981 "punching through" the (Windows XP) firewall, allowing
2982 the remainder of the TFTP transfer to proceed normally.
2983 A better solution is to properly configure the firewall,
2984 but sometimes that is not allowed.
2989 This enables a generic 'hash' command which can produce
2990 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2994 Enable the hash verify command (hash -v). This adds to code
2997 CONFIG_SHA1 - support SHA1 hashing
2998 CONFIG_SHA256 - support SHA256 hashing
3000 Note: There is also a sha1sum command, which should perhaps
3001 be deprecated in favour of 'hash sha1'.
3003 - Freescale i.MX specific commands:
3004 CONFIG_CMD_HDMIDETECT
3005 This enables 'hdmidet' command which returns true if an
3006 HDMI monitor is detected. This command is i.MX 6 specific.
3009 This enables the 'bmode' (bootmode) command for forcing
3010 a boot from specific media.
3012 This is useful for forcing the ROM's usb downloader to
3013 activate upon a watchdog reset which is nice when iterating
3014 on U-Boot. Using the reset button or running bmode normal
3015 will set it back to normal. This command currently
3016 supports i.MX53 and i.MX6.
3021 This enables the RSA algorithm used for FIT image verification
3022 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3024 The signing part is build into mkimage regardless of this
3027 - bootcount support:
3028 CONFIG_BOOTCOUNT_LIMIT
3030 This enables the bootcounter support, see:
3031 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3034 enable special bootcounter support on at91sam9xe based boards.
3036 enable special bootcounter support on blackfin based boards.
3038 enable special bootcounter support on da850 based boards.
3039 CONFIG_BOOTCOUNT_RAM
3040 enable support for the bootcounter in RAM
3041 CONFIG_BOOTCOUNT_I2C
3042 enable support for the bootcounter on an i2c (like RTC) device.
3043 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3044 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3046 CONFIG_BOOTCOUNT_ALEN = address len
3048 - Show boot progress:
3049 CONFIG_SHOW_BOOT_PROGRESS
3051 Defining this option allows to add some board-
3052 specific code (calling a user-provided function
3053 "show_boot_progress(int)") that enables you to show
3054 the system's boot progress on some display (for
3055 example, some LED's) on your board. At the moment,
3056 the following checkpoints are implemented:
3058 - Detailed boot stage timing
3060 Define this option to get detailed timing of each stage
3061 of the boot process.
3063 CONFIG_BOOTSTAGE_USER_COUNT
3064 This is the number of available user bootstage records.
3065 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3066 a new ID will be allocated from this stash. If you exceed
3067 the limit, recording will stop.
3069 CONFIG_BOOTSTAGE_REPORT
3070 Define this to print a report before boot, similar to this:
3072 Timer summary in microseconds:
3075 3,575,678 3,575,678 board_init_f start
3076 3,575,695 17 arch_cpu_init A9
3077 3,575,777 82 arch_cpu_init done
3078 3,659,598 83,821 board_init_r start
3079 3,910,375 250,777 main_loop
3080 29,916,167 26,005,792 bootm_start
3081 30,361,327 445,160 start_kernel
3083 CONFIG_CMD_BOOTSTAGE
3084 Add a 'bootstage' command which supports printing a report
3085 and un/stashing of bootstage data.
3087 CONFIG_BOOTSTAGE_FDT
3088 Stash the bootstage information in the FDT. A root 'bootstage'
3089 node is created with each bootstage id as a child. Each child
3090 has a 'name' property and either 'mark' containing the
3091 mark time in microsecond, or 'accum' containing the
3092 accumulated time for that bootstage id in microseconds.
3097 name = "board_init_f";
3106 Code in the Linux kernel can find this in /proc/devicetree.
3108 Legacy uImage format:
3111 1 common/cmd_bootm.c before attempting to boot an image
3112 -1 common/cmd_bootm.c Image header has bad magic number
3113 2 common/cmd_bootm.c Image header has correct magic number
3114 -2 common/cmd_bootm.c Image header has bad checksum
3115 3 common/cmd_bootm.c Image header has correct checksum
3116 -3 common/cmd_bootm.c Image data has bad checksum
3117 4 common/cmd_bootm.c Image data has correct checksum
3118 -4 common/cmd_bootm.c Image is for unsupported architecture
3119 5 common/cmd_bootm.c Architecture check OK
3120 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3121 6 common/cmd_bootm.c Image Type check OK
3122 -6 common/cmd_bootm.c gunzip uncompression error
3123 -7 common/cmd_bootm.c Unimplemented compression type
3124 7 common/cmd_bootm.c Uncompression OK
3125 8 common/cmd_bootm.c No uncompress/copy overwrite error
3126 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3128 9 common/image.c Start initial ramdisk verification
3129 -10 common/image.c Ramdisk header has bad magic number
3130 -11 common/image.c Ramdisk header has bad checksum
3131 10 common/image.c Ramdisk header is OK
3132 -12 common/image.c Ramdisk data has bad checksum
3133 11 common/image.c Ramdisk data has correct checksum
3134 12 common/image.c Ramdisk verification complete, start loading
3135 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3136 13 common/image.c Start multifile image verification
3137 14 common/image.c No initial ramdisk, no multifile, continue.
3139 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3141 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3142 -31 post/post.c POST test failed, detected by post_output_backlog()
3143 -32 post/post.c POST test failed, detected by post_run_single()
3145 34 common/cmd_doc.c before loading a Image from a DOC device
3146 -35 common/cmd_doc.c Bad usage of "doc" command
3147 35 common/cmd_doc.c correct usage of "doc" command
3148 -36 common/cmd_doc.c No boot device
3149 36 common/cmd_doc.c correct boot device
3150 -37 common/cmd_doc.c Unknown Chip ID on boot device
3151 37 common/cmd_doc.c correct chip ID found, device available
3152 -38 common/cmd_doc.c Read Error on boot device
3153 38 common/cmd_doc.c reading Image header from DOC device OK
3154 -39 common/cmd_doc.c Image header has bad magic number
3155 39 common/cmd_doc.c Image header has correct magic number
3156 -40 common/cmd_doc.c Error reading Image from DOC device
3157 40 common/cmd_doc.c Image header has correct magic number
3158 41 common/cmd_ide.c before loading a Image from a IDE device
3159 -42 common/cmd_ide.c Bad usage of "ide" command
3160 42 common/cmd_ide.c correct usage of "ide" command
3161 -43 common/cmd_ide.c No boot device
3162 43 common/cmd_ide.c boot device found
3163 -44 common/cmd_ide.c Device not available
3164 44 common/cmd_ide.c Device available
3165 -45 common/cmd_ide.c wrong partition selected
3166 45 common/cmd_ide.c partition selected
3167 -46 common/cmd_ide.c Unknown partition table
3168 46 common/cmd_ide.c valid partition table found
3169 -47 common/cmd_ide.c Invalid partition type
3170 47 common/cmd_ide.c correct partition type
3171 -48 common/cmd_ide.c Error reading Image Header on boot device
3172 48 common/cmd_ide.c reading Image Header from IDE device OK
3173 -49 common/cmd_ide.c Image header has bad magic number
3174 49 common/cmd_ide.c Image header has correct magic number
3175 -50 common/cmd_ide.c Image header has bad checksum
3176 50 common/cmd_ide.c Image header has correct checksum
3177 -51 common/cmd_ide.c Error reading Image from IDE device
3178 51 common/cmd_ide.c reading Image from IDE device OK
3179 52 common/cmd_nand.c before loading a Image from a NAND device
3180 -53 common/cmd_nand.c Bad usage of "nand" command
3181 53 common/cmd_nand.c correct usage of "nand" command
3182 -54 common/cmd_nand.c No boot device
3183 54 common/cmd_nand.c boot device found
3184 -55 common/cmd_nand.c Unknown Chip ID on boot device
3185 55 common/cmd_nand.c correct chip ID found, device available
3186 -56 common/cmd_nand.c Error reading Image Header on boot device
3187 56 common/cmd_nand.c reading Image Header from NAND device OK
3188 -57 common/cmd_nand.c Image header has bad magic number
3189 57 common/cmd_nand.c Image header has correct magic number
3190 -58 common/cmd_nand.c Error reading Image from NAND device
3191 58 common/cmd_nand.c reading Image from NAND device OK
3193 -60 common/env_common.c Environment has a bad CRC, using default
3195 64 net/eth.c starting with Ethernet configuration.
3196 -64 net/eth.c no Ethernet found.
3197 65 net/eth.c Ethernet found.
3199 -80 common/cmd_net.c usage wrong
3200 80 common/cmd_net.c before calling NetLoop()
3201 -81 common/cmd_net.c some error in NetLoop() occurred
3202 81 common/cmd_net.c NetLoop() back without error
3203 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3204 82 common/cmd_net.c trying automatic boot
3205 83 common/cmd_net.c running "source" command
3206 -83 common/cmd_net.c some error in automatic boot or "source" command
3207 84 common/cmd_net.c end without errors
3212 100 common/cmd_bootm.c Kernel FIT Image has correct format
3213 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3214 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3215 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3216 102 common/cmd_bootm.c Kernel unit name specified
3217 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3218 103 common/cmd_bootm.c Found configuration node
3219 104 common/cmd_bootm.c Got kernel subimage node offset
3220 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3221 105 common/cmd_bootm.c Kernel subimage hash verification OK
3222 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3223 106 common/cmd_bootm.c Architecture check OK
3224 -106 common/cmd_bootm.c Kernel subimage has wrong type
3225 107 common/cmd_bootm.c Kernel subimage type OK
3226 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3227 108 common/cmd_bootm.c Got kernel subimage data/size
3228 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3229 -109 common/cmd_bootm.c Can't get kernel subimage type
3230 -110 common/cmd_bootm.c Can't get kernel subimage comp
3231 -111 common/cmd_bootm.c Can't get kernel subimage os
3232 -112 common/cmd_bootm.c Can't get kernel subimage load address
3233 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3235 120 common/image.c Start initial ramdisk verification
3236 -120 common/image.c Ramdisk FIT image has incorrect format
3237 121 common/image.c Ramdisk FIT image has correct format
3238 122 common/image.c No ramdisk subimage unit name, using configuration
3239 -122 common/image.c Can't get configuration for ramdisk subimage
3240 123 common/image.c Ramdisk unit name specified
3241 -124 common/image.c Can't get ramdisk subimage node offset
3242 125 common/image.c Got ramdisk subimage node offset
3243 -125 common/image.c Ramdisk subimage hash verification failed
3244 126 common/image.c Ramdisk subimage hash verification OK
3245 -126 common/image.c Ramdisk subimage for unsupported architecture
3246 127 common/image.c Architecture check OK
3247 -127 common/image.c Can't get ramdisk subimage data/size
3248 128 common/image.c Got ramdisk subimage data/size
3249 129 common/image.c Can't get ramdisk load address
3250 -129 common/image.c Got ramdisk load address
3252 -130 common/cmd_doc.c Incorrect FIT image format
3253 131 common/cmd_doc.c FIT image format OK
3255 -140 common/cmd_ide.c Incorrect FIT image format
3256 141 common/cmd_ide.c FIT image format OK
3258 -150 common/cmd_nand.c Incorrect FIT image format
3259 151 common/cmd_nand.c FIT image format OK
3261 - legacy image format:
3262 CONFIG_IMAGE_FORMAT_LEGACY
3263 enables the legacy image format support in U-Boot.
3266 enabled if CONFIG_FIT_SIGNATURE is not defined.
3268 CONFIG_DISABLE_IMAGE_LEGACY
3269 disable the legacy image format
3271 This define is introduced, as the legacy image format is
3272 enabled per default for backward compatibility.
3274 - FIT image support:
3276 Enable support for the FIT uImage format.
3278 CONFIG_FIT_BEST_MATCH
3279 When no configuration is explicitly selected, default to the
3280 one whose fdt's compatibility field best matches that of
3281 U-Boot itself. A match is considered "best" if it matches the
3282 most specific compatibility entry of U-Boot's fdt's root node.
3283 The order of entries in the configuration's fdt is ignored.
3285 CONFIG_FIT_SIGNATURE
3286 This option enables signature verification of FIT uImages,
3287 using a hash signed and verified using RSA. See
3288 doc/uImage.FIT/signature.txt for more details.
3290 WARNING: When relying on signed FIT images with required
3291 signature check the legacy image format is default
3292 disabled. If a board need legacy image format support
3293 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3295 CONFIG_FIT_DISABLE_SHA256
3296 Supporting SHA256 hashes has quite an impact on binary size.
3297 For constrained systems sha256 hash support can be disabled
3300 - Standalone program support:
3301 CONFIG_STANDALONE_LOAD_ADDR
3303 This option defines a board specific value for the
3304 address where standalone program gets loaded, thus
3305 overwriting the architecture dependent default
3308 - Frame Buffer Address:
3311 Define CONFIG_FB_ADDR if you want to use specific
3312 address for frame buffer. This is typically the case
3313 when using a graphics controller has separate video
3314 memory. U-Boot will then place the frame buffer at
3315 the given address instead of dynamically reserving it
3316 in system RAM by calling lcd_setmem(), which grabs
3317 the memory for the frame buffer depending on the
3318 configured panel size.
3320 Please see board_init_f function.
3322 - Automatic software updates via TFTP server
3324 CONFIG_UPDATE_TFTP_CNT_MAX
3325 CONFIG_UPDATE_TFTP_MSEC_MAX
3327 These options enable and control the auto-update feature;
3328 for a more detailed description refer to doc/README.update.
3330 - MTD Support (mtdparts command, UBI support)
3333 Adds the MTD device infrastructure from the Linux kernel.
3334 Needed for mtdparts command support.
3336 CONFIG_MTD_PARTITIONS
3338 Adds the MTD partitioning infrastructure from the Linux
3339 kernel. Needed for UBI support.
3344 Adds commands for interacting with MTD partitions formatted
3345 with the UBI flash translation layer
3347 Requires also defining CONFIG_RBTREE
3349 CONFIG_UBI_SILENCE_MSG
3351 Make the verbose messages from UBI stop printing. This leaves
3352 warnings and errors enabled.
3357 Adds commands for interacting with UBI volumes formatted as
3358 UBIFS. UBIFS is read-only in u-boot.
3360 Requires UBI support as well as CONFIG_LZO
3362 CONFIG_UBIFS_SILENCE_MSG
3364 Make the verbose messages from UBIFS stop printing. This leaves
3365 warnings and errors enabled.
3369 Enable building of SPL globally.
3372 LDSCRIPT for linking the SPL binary.
3374 CONFIG_SPL_MAX_FOOTPRINT
3375 Maximum size in memory allocated to the SPL, BSS included.
3376 When defined, the linker checks that the actual memory
3377 used by SPL from _start to __bss_end does not exceed it.
3378 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3379 must not be both defined at the same time.
3382 Maximum size of the SPL image (text, data, rodata, and
3383 linker lists sections), BSS excluded.
3384 When defined, the linker checks that the actual size does
3387 CONFIG_SPL_TEXT_BASE
3388 TEXT_BASE for linking the SPL binary.
3390 CONFIG_SPL_RELOC_TEXT_BASE
3391 Address to relocate to. If unspecified, this is equal to
3392 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3394 CONFIG_SPL_BSS_START_ADDR
3395 Link address for the BSS within the SPL binary.
3397 CONFIG_SPL_BSS_MAX_SIZE
3398 Maximum size in memory allocated to the SPL BSS.
3399 When defined, the linker checks that the actual memory used
3400 by SPL from __bss_start to __bss_end does not exceed it.
3401 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3402 must not be both defined at the same time.
3405 Adress of the start of the stack SPL will use
3407 CONFIG_SPL_RELOC_STACK
3408 Adress of the start of the stack SPL will use after
3409 relocation. If unspecified, this is equal to
3412 CONFIG_SYS_SPL_MALLOC_START
3413 Starting address of the malloc pool used in SPL.
3415 CONFIG_SYS_SPL_MALLOC_SIZE
3416 The size of the malloc pool used in SPL.
3418 CONFIG_SPL_FRAMEWORK
3419 Enable the SPL framework under common/. This framework
3420 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3421 NAND loading of the Linux Kernel.
3424 Enable booting directly to an OS from SPL.
3425 See also: doc/README.falcon
3427 CONFIG_SPL_DISPLAY_PRINT
3428 For ARM, enable an optional function to print more information
3429 about the running system.
3431 CONFIG_SPL_INIT_MINIMAL
3432 Arch init code should be built for a very small image
3434 CONFIG_SPL_LIBCOMMON_SUPPORT
3435 Support for common/libcommon.o in SPL binary
3437 CONFIG_SPL_LIBDISK_SUPPORT
3438 Support for disk/libdisk.o in SPL binary
3440 CONFIG_SPL_I2C_SUPPORT
3441 Support for drivers/i2c/libi2c.o in SPL binary
3443 CONFIG_SPL_GPIO_SUPPORT
3444 Support for drivers/gpio/libgpio.o in SPL binary
3446 CONFIG_SPL_MMC_SUPPORT
3447 Support for drivers/mmc/libmmc.o in SPL binary
3449 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3450 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3451 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3452 Address, size and partition on the MMC to load U-Boot from
3453 when the MMC is being used in raw mode.
3455 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3456 Sector to load kernel uImage from when MMC is being
3457 used in raw mode (for Falcon mode)
3459 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3460 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3461 Sector and number of sectors to load kernel argument
3462 parameters from when MMC is being used in raw mode
3465 CONFIG_SPL_FAT_SUPPORT
3466 Support for fs/fat/libfat.o in SPL binary
3468 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3469 Filename to read to load U-Boot when reading from FAT
3471 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3472 Filename to read to load kernel uImage when reading
3473 from FAT (for Falcon mode)
3475 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3476 Filename to read to load kernel argument parameters
3477 when reading from FAT (for Falcon mode)
3479 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3480 Set this for NAND SPL on PPC mpc83xx targets, so that
3481 start.S waits for the rest of the SPL to load before
3482 continuing (the hardware starts execution after just
3483 loading the first page rather than the full 4K).
3485 CONFIG_SPL_SKIP_RELOCATE
3486 Avoid SPL relocation
3488 CONFIG_SPL_NAND_BASE
3489 Include nand_base.c in the SPL. Requires
3490 CONFIG_SPL_NAND_DRIVERS.
3492 CONFIG_SPL_NAND_DRIVERS
3493 SPL uses normal NAND drivers, not minimal drivers.
3496 Include standard software ECC in the SPL
3498 CONFIG_SPL_NAND_SIMPLE
3499 Support for NAND boot using simple NAND drivers that
3500 expose the cmd_ctrl() interface.
3502 CONFIG_SPL_MTD_SUPPORT
3503 Support for the MTD subsystem within SPL. Useful for
3504 environment on NAND support within SPL.
3506 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3507 Set for the SPL on PPC mpc8xxx targets, support for
3508 drivers/ddr/fsl/libddr.o in SPL binary.
3510 CONFIG_SPL_COMMON_INIT_DDR
3511 Set for common ddr init with serial presence detect in
3514 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3515 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3516 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3517 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3518 CONFIG_SYS_NAND_ECCBYTES
3519 Defines the size and behavior of the NAND that SPL uses
3522 CONFIG_SPL_NAND_BOOT
3523 Add support NAND boot
3525 CONFIG_SYS_NAND_U_BOOT_OFFS
3526 Location in NAND to read U-Boot from
3528 CONFIG_SYS_NAND_U_BOOT_DST
3529 Location in memory to load U-Boot to
3531 CONFIG_SYS_NAND_U_BOOT_SIZE
3532 Size of image to load
3534 CONFIG_SYS_NAND_U_BOOT_START
3535 Entry point in loaded image to jump to
3537 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3538 Define this if you need to first read the OOB and then the
3539 data. This is used for example on davinci plattforms.
3541 CONFIG_SPL_OMAP3_ID_NAND
3542 Support for an OMAP3-specific set of functions to return the
3543 ID and MFR of the first attached NAND chip, if present.
3545 CONFIG_SPL_SERIAL_SUPPORT
3546 Support for drivers/serial/libserial.o in SPL binary
3548 CONFIG_SPL_SPI_FLASH_SUPPORT
3549 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3551 CONFIG_SPL_SPI_SUPPORT
3552 Support for drivers/spi/libspi.o in SPL binary
3554 CONFIG_SPL_RAM_DEVICE
3555 Support for running image already present in ram, in SPL binary
3557 CONFIG_SPL_LIBGENERIC_SUPPORT
3558 Support for lib/libgeneric.o in SPL binary
3560 CONFIG_SPL_ENV_SUPPORT
3561 Support for the environment operating in SPL binary
3563 CONFIG_SPL_NET_SUPPORT
3564 Support for the net/libnet.o in SPL binary.
3565 It conflicts with SPL env from storage medium specified by
3566 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3569 Image offset to which the SPL should be padded before appending
3570 the SPL payload. By default, this is defined as
3571 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3572 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3573 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3576 Final target image containing SPL and payload. Some SPLs
3577 use an arch-specific makefile fragment instead, for
3578 example if more than one image needs to be produced.
3580 CONFIG_FIT_SPL_PRINT
3581 Printing information about a FIT image adds quite a bit of
3582 code to SPL. So this is normally disabled in SPL. Use this
3583 option to re-enable it. This will affect the output of the
3584 bootm command when booting a FIT image.
3588 Enable building of TPL globally.
3591 Image offset to which the TPL should be padded before appending
3592 the TPL payload. By default, this is defined as
3593 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3594 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3595 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3600 [so far only for SMDK2400 boards]
3602 - Modem support enable:
3603 CONFIG_MODEM_SUPPORT
3605 - RTS/CTS Flow control enable:
3608 - Modem debug support:
3609 CONFIG_MODEM_SUPPORT_DEBUG
3611 Enables debugging stuff (char screen[1024], dbg())
3612 for modem support. Useful only with BDI2000.
3614 - Interrupt support (PPC):
3616 There are common interrupt_init() and timer_interrupt()
3617 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3618 for CPU specific initialization. interrupt_init_cpu()
3619 should set decrementer_count to appropriate value. If
3620 CPU resets decrementer automatically after interrupt
3621 (ppc4xx) it should set decrementer_count to zero.
3622 timer_interrupt() calls timer_interrupt_cpu() for CPU
3623 specific handling. If board has watchdog / status_led
3624 / other_activity_monitor it works automatically from
3625 general timer_interrupt().
3629 In the target system modem support is enabled when a
3630 specific key (key combination) is pressed during
3631 power-on. Otherwise U-Boot will boot normally
3632 (autoboot). The key_pressed() function is called from
3633 board_init(). Currently key_pressed() is a dummy
3634 function, returning 1 and thus enabling modem
3637 If there are no modem init strings in the
3638 environment, U-Boot proceed to autoboot; the
3639 previous output (banner, info printfs) will be
3642 See also: doc/README.Modem
3644 Board initialization settings:
3645 ------------------------------
3647 During Initialization u-boot calls a number of board specific functions
3648 to allow the preparation of board specific prerequisites, e.g. pin setup
3649 before drivers are initialized. To enable these callbacks the
3650 following configuration macros have to be defined. Currently this is
3651 architecture specific, so please check arch/your_architecture/lib/board.c
3652 typically in board_init_f() and board_init_r().
3654 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3655 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3656 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3657 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3659 Configuration Settings:
3660 -----------------------
3662 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3663 Optionally it can be defined to support 64-bit memory commands.
3665 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3666 undefine this when you're short of memory.
3668 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3669 width of the commands listed in the 'help' command output.
3671 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3672 prompt for user input.
3674 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3676 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3678 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3680 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3681 the application (usually a Linux kernel) when it is
3684 - CONFIG_SYS_BAUDRATE_TABLE:
3685 List of legal baudrate settings for this board.
3687 - CONFIG_SYS_CONSOLE_INFO_QUIET
3688 Suppress display of console information at boot.
3690 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3691 If the board specific function
3692 extern int overwrite_console (void);
3693 returns 1, the stdin, stderr and stdout are switched to the
3694 serial port, else the settings in the environment are used.
3696 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3697 Enable the call to overwrite_console().
3699 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3700 Enable overwrite of previous console environment settings.
3702 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3703 Begin and End addresses of the area used by the
3706 - CONFIG_SYS_ALT_MEMTEST:
3707 Enable an alternate, more extensive memory test.
3709 - CONFIG_SYS_MEMTEST_SCRATCH:
3710 Scratch address used by the alternate memory test
3711 You only need to set this if address zero isn't writeable
3713 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3714 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3715 this specified memory area will get subtracted from the top
3716 (end) of RAM and won't get "touched" at all by U-Boot. By
3717 fixing up gd->ram_size the Linux kernel should gets passed
3718 the now "corrected" memory size and won't touch it either.
3719 This should work for arch/ppc and arch/powerpc. Only Linux
3720 board ports in arch/powerpc with bootwrapper support that
3721 recalculate the memory size from the SDRAM controller setup
3722 will have to get fixed in Linux additionally.
3724 This option can be used as a workaround for the 440EPx/GRx
3725 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3728 WARNING: Please make sure that this value is a multiple of
3729 the Linux page size (normally 4k). If this is not the case,
3730 then the end address of the Linux memory will be located at a
3731 non page size aligned address and this could cause major
3734 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3735 Enable temporary baudrate change while serial download
3737 - CONFIG_SYS_SDRAM_BASE:
3738 Physical start address of SDRAM. _Must_ be 0 here.
3740 - CONFIG_SYS_MBIO_BASE:
3741 Physical start address of Motherboard I/O (if using a
3744 - CONFIG_SYS_FLASH_BASE:
3745 Physical start address of Flash memory.
3747 - CONFIG_SYS_MONITOR_BASE:
3748 Physical start address of boot monitor code (set by
3749 make config files to be same as the text base address
3750 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3751 CONFIG_SYS_FLASH_BASE when booting from flash.
3753 - CONFIG_SYS_MONITOR_LEN:
3754 Size of memory reserved for monitor code, used to
3755 determine _at_compile_time_ (!) if the environment is
3756 embedded within the U-Boot image, or in a separate
3759 - CONFIG_SYS_MALLOC_LEN:
3760 Size of DRAM reserved for malloc() use.
3762 - CONFIG_SYS_MALLOC_F_LEN
3763 Size of the malloc() pool for use before relocation. If
3764 this is defined, then a very simple malloc() implementation
3765 will become available before relocation. The address is just
3766 below the global data, and the stack is moved down to make
3769 This feature allocates regions with increasing addresses
3770 within the region. calloc() is supported, but realloc()
3771 is not available. free() is supported but does nothing.
3772 The memory will be freed (or in fact just forgotton) when
3773 U-Boot relocates itself.
3775 Pre-relocation malloc() is only supported on sandbox
3776 at present but is fairly easy to enable for other archs.
3778 Pre-relocation malloc() is only supported on ARM at present
3779 but is fairly easy to enable for other archs.
3781 - CONFIG_SYS_BOOTM_LEN:
3782 Normally compressed uImages are limited to an
3783 uncompressed size of 8 MBytes. If this is not enough,
3784 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3785 to adjust this setting to your needs.
3787 - CONFIG_SYS_BOOTMAPSZ:
3788 Maximum size of memory mapped by the startup code of
3789 the Linux kernel; all data that must be processed by
3790 the Linux kernel (bd_info, boot arguments, FDT blob if
3791 used) must be put below this limit, unless "bootm_low"
3792 environment variable is defined and non-zero. In such case
3793 all data for the Linux kernel must be between "bootm_low"
3794 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3795 variable "bootm_mapsize" will override the value of
3796 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3797 then the value in "bootm_size" will be used instead.
3799 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3800 Enable initrd_high functionality. If defined then the
3801 initrd_high feature is enabled and the bootm ramdisk subcommand
3804 - CONFIG_SYS_BOOT_GET_CMDLINE:
3805 Enables allocating and saving kernel cmdline in space between
3806 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3808 - CONFIG_SYS_BOOT_GET_KBD:
3809 Enables allocating and saving a kernel copy of the bd_info in
3810 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3812 - CONFIG_SYS_MAX_FLASH_BANKS:
3813 Max number of Flash memory banks
3815 - CONFIG_SYS_MAX_FLASH_SECT:
3816 Max number of sectors on a Flash chip
3818 - CONFIG_SYS_FLASH_ERASE_TOUT:
3819 Timeout for Flash erase operations (in ms)
3821 - CONFIG_SYS_FLASH_WRITE_TOUT:
3822 Timeout for Flash write operations (in ms)
3824 - CONFIG_SYS_FLASH_LOCK_TOUT
3825 Timeout for Flash set sector lock bit operation (in ms)
3827 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3828 Timeout for Flash clear lock bits operation (in ms)
3830 - CONFIG_SYS_FLASH_PROTECTION
3831 If defined, hardware flash sectors protection is used
3832 instead of U-Boot software protection.
3834 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3836 Enable TFTP transfers directly to flash memory;
3837 without this option such a download has to be
3838 performed in two steps: (1) download to RAM, and (2)
3839 copy from RAM to flash.
3841 The two-step approach is usually more reliable, since
3842 you can check if the download worked before you erase
3843 the flash, but in some situations (when system RAM is
3844 too limited to allow for a temporary copy of the
3845 downloaded image) this option may be very useful.
3847 - CONFIG_SYS_FLASH_CFI:
3848 Define if the flash driver uses extra elements in the
3849 common flash structure for storing flash geometry.
3851 - CONFIG_FLASH_CFI_DRIVER
3852 This option also enables the building of the cfi_flash driver
3853 in the drivers directory
3855 - CONFIG_FLASH_CFI_MTD
3856 This option enables the building of the cfi_mtd driver
3857 in the drivers directory. The driver exports CFI flash
3860 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3861 Use buffered writes to flash.
3863 - CONFIG_FLASH_SPANSION_S29WS_N
3864 s29ws-n MirrorBit flash has non-standard addresses for buffered
3867 - CONFIG_SYS_FLASH_QUIET_TEST
3868 If this option is defined, the common CFI flash doesn't
3869 print it's warning upon not recognized FLASH banks. This
3870 is useful, if some of the configured banks are only
3871 optionally available.
3873 - CONFIG_FLASH_SHOW_PROGRESS
3874 If defined (must be an integer), print out countdown
3875 digits and dots. Recommended value: 45 (9..1) for 80
3876 column displays, 15 (3..1) for 40 column displays.
3878 - CONFIG_FLASH_VERIFY
3879 If defined, the content of the flash (destination) is compared
3880 against the source after the write operation. An error message
3881 will be printed when the contents are not identical.
3882 Please note that this option is useless in nearly all cases,
3883 since such flash programming errors usually are detected earlier
3884 while unprotecting/erasing/programming. Please only enable
3885 this option if you really know what you are doing.
3887 - CONFIG_SYS_RX_ETH_BUFFER:
3888 Defines the number of Ethernet receive buffers. On some
3889 Ethernet controllers it is recommended to set this value
3890 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3891 buffers can be full shortly after enabling the interface
3892 on high Ethernet traffic.
3893 Defaults to 4 if not defined.
3895 - CONFIG_ENV_MAX_ENTRIES
3897 Maximum number of entries in the hash table that is used
3898 internally to store the environment settings. The default
3899 setting is supposed to be generous and should work in most
3900 cases. This setting can be used to tune behaviour; see
3901 lib/hashtable.c for details.
3903 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3904 - CONFIG_ENV_FLAGS_LIST_STATIC
3905 Enable validation of the values given to environment variables when
3906 calling env set. Variables can be restricted to only decimal,
3907 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3908 the variables can also be restricted to IP address or MAC address.
3910 The format of the list is:
3911 type_attribute = [s|d|x|b|i|m]
3912 access_atribute = [a|r|o|c]
3913 attributes = type_attribute[access_atribute]
3914 entry = variable_name[:attributes]
3917 The type attributes are:
3918 s - String (default)
3921 b - Boolean ([1yYtT|0nNfF])
3925 The access attributes are:
3931 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3932 Define this to a list (string) to define the ".flags"
3933 envirnoment variable in the default or embedded environment.
3935 - CONFIG_ENV_FLAGS_LIST_STATIC
3936 Define this to a list (string) to define validation that
3937 should be done if an entry is not found in the ".flags"
3938 environment variable. To override a setting in the static
3939 list, simply add an entry for the same variable name to the
3942 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3943 If defined, don't allow the -f switch to env set override variable
3946 - CONFIG_SYS_GENERIC_BOARD
3947 This selects the architecture-generic board system instead of the
3948 architecture-specific board files. It is intended to move boards
3949 to this new framework over time. Defining this will disable the
3950 arch/foo/lib/board.c file and use common/board_f.c and
3951 common/board_r.c instead. To use this option your architecture
3952 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3953 its config.mk file). If you find problems enabling this option on
3954 your board please report the problem and send patches!
3956 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3957 This is set by OMAP boards for the max time that reset should
3958 be asserted. See doc/README.omap-reset-time for details on how
3959 the value can be calulated on a given board.
3961 The following definitions that deal with the placement and management
3962 of environment data (variable area); in general, we support the
3963 following configurations:
3965 - CONFIG_BUILD_ENVCRC:
3967 Builds up envcrc with the target environment so that external utils
3968 may easily extract it and embed it in final U-Boot images.
3970 - CONFIG_ENV_IS_IN_FLASH:
3972 Define this if the environment is in flash memory.
3974 a) The environment occupies one whole flash sector, which is
3975 "embedded" in the text segment with the U-Boot code. This
3976 happens usually with "bottom boot sector" or "top boot
3977 sector" type flash chips, which have several smaller
3978 sectors at the start or the end. For instance, such a
3979 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3980 such a case you would place the environment in one of the
3981 4 kB sectors - with U-Boot code before and after it. With
3982 "top boot sector" type flash chips, you would put the
3983 environment in one of the last sectors, leaving a gap
3984 between U-Boot and the environment.
3986 - CONFIG_ENV_OFFSET:
3988 Offset of environment data (variable area) to the
3989 beginning of flash memory; for instance, with bottom boot
3990 type flash chips the second sector can be used: the offset
3991 for this sector is given here.
3993 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3997 This is just another way to specify the start address of
3998 the flash sector containing the environment (instead of
4001 - CONFIG_ENV_SECT_SIZE:
4003 Size of the sector containing the environment.
4006 b) Sometimes flash chips have few, equal sized, BIG sectors.
4007 In such a case you don't want to spend a whole sector for
4012 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4013 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4014 of this flash sector for the environment. This saves
4015 memory for the RAM copy of the environment.
4017 It may also save flash memory if you decide to use this
4018 when your environment is "embedded" within U-Boot code,
4019 since then the remainder of the flash sector could be used
4020 for U-Boot code. It should be pointed out that this is
4021 STRONGLY DISCOURAGED from a robustness point of view:
4022 updating the environment in flash makes it always
4023 necessary to erase the WHOLE sector. If something goes
4024 wrong before the contents has been restored from a copy in
4025 RAM, your target system will be dead.
4027 - CONFIG_ENV_ADDR_REDUND
4028 CONFIG_ENV_SIZE_REDUND
4030 These settings describe a second storage area used to hold
4031 a redundant copy of the environment data, so that there is
4032 a valid backup copy in case there is a power failure during
4033 a "saveenv" operation.
4035 BE CAREFUL! Any changes to the flash layout, and some changes to the
4036 source code will make it necessary to adapt <board>/u-boot.lds*
4040 - CONFIG_ENV_IS_IN_NVRAM:
4042 Define this if you have some non-volatile memory device
4043 (NVRAM, battery buffered SRAM) which you want to use for the
4049 These two #defines are used to determine the memory area you
4050 want to use for environment. It is assumed that this memory
4051 can just be read and written to, without any special
4054 BE CAREFUL! The first access to the environment happens quite early
4055 in U-Boot initalization (when we try to get the setting of for the
4056 console baudrate). You *MUST* have mapped your NVRAM area then, or
4059 Please note that even with NVRAM we still use a copy of the
4060 environment in RAM: we could work on NVRAM directly, but we want to
4061 keep settings there always unmodified except somebody uses "saveenv"
4062 to save the current settings.
4065 - CONFIG_ENV_IS_IN_EEPROM:
4067 Use this if you have an EEPROM or similar serial access
4068 device and a driver for it.
4070 - CONFIG_ENV_OFFSET:
4073 These two #defines specify the offset and size of the
4074 environment area within the total memory of your EEPROM.
4076 - CONFIG_SYS_I2C_EEPROM_ADDR:
4077 If defined, specified the chip address of the EEPROM device.
4078 The default address is zero.
4080 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4081 If defined, the number of bits used to address bytes in a
4082 single page in the EEPROM device. A 64 byte page, for example
4083 would require six bits.
4085 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4086 If defined, the number of milliseconds to delay between
4087 page writes. The default is zero milliseconds.
4089 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4090 The length in bytes of the EEPROM memory array address. Note
4091 that this is NOT the chip address length!
4093 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4094 EEPROM chips that implement "address overflow" are ones
4095 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4096 address and the extra bits end up in the "chip address" bit
4097 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4100 Note that we consider the length of the address field to
4101 still be one byte because the extra address bits are hidden
4102 in the chip address.
4104 - CONFIG_SYS_EEPROM_SIZE:
4105 The size in bytes of the EEPROM device.
4107 - CONFIG_ENV_EEPROM_IS_ON_I2C
4108 define this, if you have I2C and SPI activated, and your
4109 EEPROM, which holds the environment, is on the I2C bus.
4111 - CONFIG_I2C_ENV_EEPROM_BUS
4112 if you have an Environment on an EEPROM reached over
4113 I2C muxes, you can define here, how to reach this
4114 EEPROM. For example:
4116 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4118 EEPROM which holds the environment, is reached over
4119 a pca9547 i2c mux with address 0x70, channel 3.
4121 - CONFIG_ENV_IS_IN_DATAFLASH:
4123 Define this if you have a DataFlash memory device which you
4124 want to use for the environment.
4126 - CONFIG_ENV_OFFSET:
4130 These three #defines specify the offset and size of the
4131 environment area within the total memory of your DataFlash placed
4132 at the specified address.
4134 - CONFIG_ENV_IS_IN_SPI_FLASH:
4136 Define this if you have a SPI Flash memory device which you
4137 want to use for the environment.
4139 - CONFIG_ENV_OFFSET:
4142 These two #defines specify the offset and size of the
4143 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4144 aligned to an erase sector boundary.
4146 - CONFIG_ENV_SECT_SIZE:
4148 Define the SPI flash's sector size.
4150 - CONFIG_ENV_OFFSET_REDUND (optional):
4152 This setting describes a second storage area of CONFIG_ENV_SIZE
4153 size used to hold a redundant copy of the environment data, so
4154 that there is a valid backup copy in case there is a power failure
4155 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4156 aligned to an erase sector boundary.
4158 - CONFIG_ENV_SPI_BUS (optional):
4159 - CONFIG_ENV_SPI_CS (optional):
4161 Define the SPI bus and chip select. If not defined they will be 0.
4163 - CONFIG_ENV_SPI_MAX_HZ (optional):
4165 Define the SPI max work clock. If not defined then use 1MHz.
4167 - CONFIG_ENV_SPI_MODE (optional):
4169 Define the SPI work mode. If not defined then use SPI_MODE_3.
4171 - CONFIG_ENV_IS_IN_REMOTE:
4173 Define this if you have a remote memory space which you
4174 want to use for the local device's environment.
4179 These two #defines specify the address and size of the
4180 environment area within the remote memory space. The
4181 local device can get the environment from remote memory
4182 space by SRIO or PCIE links.
4184 BE CAREFUL! For some special cases, the local device can not use
4185 "saveenv" command. For example, the local device will get the
4186 environment stored in a remote NOR flash by SRIO or PCIE link,
4187 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4189 - CONFIG_ENV_IS_IN_NAND:
4191 Define this if you have a NAND device which you want to use
4192 for the environment.
4194 - CONFIG_ENV_OFFSET:
4197 These two #defines specify the offset and size of the environment
4198 area within the first NAND device. CONFIG_ENV_OFFSET must be
4199 aligned to an erase block boundary.
4201 - CONFIG_ENV_OFFSET_REDUND (optional):
4203 This setting describes a second storage area of CONFIG_ENV_SIZE
4204 size used to hold a redundant copy of the environment data, so
4205 that there is a valid backup copy in case there is a power failure
4206 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4207 aligned to an erase block boundary.
4209 - CONFIG_ENV_RANGE (optional):
4211 Specifies the length of the region in which the environment
4212 can be written. This should be a multiple of the NAND device's
4213 block size. Specifying a range with more erase blocks than
4214 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4215 the range to be avoided.
4217 - CONFIG_ENV_OFFSET_OOB (optional):
4219 Enables support for dynamically retrieving the offset of the
4220 environment from block zero's out-of-band data. The
4221 "nand env.oob" command can be used to record this offset.
4222 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4223 using CONFIG_ENV_OFFSET_OOB.
4225 - CONFIG_NAND_ENV_DST
4227 Defines address in RAM to which the nand_spl code should copy the
4228 environment. If redundant environment is used, it will be copied to
4229 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4231 - CONFIG_ENV_IS_IN_UBI:
4233 Define this if you have an UBI volume that you want to use for the
4234 environment. This has the benefit of wear-leveling the environment
4235 accesses, which is important on NAND.
4237 - CONFIG_ENV_UBI_PART:
4239 Define this to a string that is the mtd partition containing the UBI.
4241 - CONFIG_ENV_UBI_VOLUME:
4243 Define this to the name of the volume that you want to store the
4246 - CONFIG_ENV_UBI_VOLUME_REDUND:
4248 Define this to the name of another volume to store a second copy of
4249 the environment in. This will enable redundant environments in UBI.
4250 It is assumed that both volumes are in the same MTD partition.
4252 - CONFIG_UBI_SILENCE_MSG
4253 - CONFIG_UBIFS_SILENCE_MSG
4255 You will probably want to define these to avoid a really noisy system
4256 when storing the env in UBI.
4258 - CONFIG_ENV_IS_IN_FAT:
4259 Define this if you want to use the FAT file system for the environment.
4261 - FAT_ENV_INTERFACE:
4263 Define this to a string that is the name of the block device.
4265 - FAT_ENV_DEV_AND_PART:
4267 Define this to a string to specify the partition of the device. It can
4270 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4271 - "D:P": device D partition P. Error occurs if device D has no
4274 - "D" or "D:": device D partition 1 if device D has partition
4275 table, or the whole device D if has no partition
4277 - "D:auto": first partition in device D with bootable flag set.
4278 If none, first valid paratition in device D. If no
4279 partition table then means device D.
4283 It's a string of the FAT file name. This file use to store the
4287 This should be defined. Otherwise it cannot save the envrionment file.
4289 - CONFIG_ENV_IS_IN_MMC:
4291 Define this if you have an MMC device which you want to use for the
4294 - CONFIG_SYS_MMC_ENV_DEV:
4296 Specifies which MMC device the environment is stored in.
4298 - CONFIG_SYS_MMC_ENV_PART (optional):
4300 Specifies which MMC partition the environment is stored in. If not
4301 set, defaults to partition 0, the user area. Common values might be
4302 1 (first MMC boot partition), 2 (second MMC boot partition).
4304 - CONFIG_ENV_OFFSET:
4307 These two #defines specify the offset and size of the environment
4308 area within the specified MMC device.
4310 If offset is positive (the usual case), it is treated as relative to
4311 the start of the MMC partition. If offset is negative, it is treated
4312 as relative to the end of the MMC partition. This can be useful if
4313 your board may be fitted with different MMC devices, which have
4314 different sizes for the MMC partitions, and you always want the
4315 environment placed at the very end of the partition, to leave the
4316 maximum possible space before it, to store other data.
4318 These two values are in units of bytes, but must be aligned to an
4319 MMC sector boundary.
4321 - CONFIG_ENV_OFFSET_REDUND (optional):
4323 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4324 hold a redundant copy of the environment data. This provides a
4325 valid backup copy in case the other copy is corrupted, e.g. due
4326 to a power failure during a "saveenv" operation.
4328 This value may also be positive or negative; this is handled in the
4329 same way as CONFIG_ENV_OFFSET.
4331 This value is also in units of bytes, but must also be aligned to
4332 an MMC sector boundary.
4334 - CONFIG_ENV_SIZE_REDUND (optional):
4336 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4337 set. If this value is set, it must be set to the same value as
4340 - CONFIG_SYS_SPI_INIT_OFFSET
4342 Defines offset to the initial SPI buffer area in DPRAM. The
4343 area is used at an early stage (ROM part) if the environment
4344 is configured to reside in the SPI EEPROM: We need a 520 byte
4345 scratch DPRAM area. It is used between the two initialization
4346 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4347 to be a good choice since it makes it far enough from the
4348 start of the data area as well as from the stack pointer.
4350 Please note that the environment is read-only until the monitor
4351 has been relocated to RAM and a RAM copy of the environment has been
4352 created; also, when using EEPROM you will have to use getenv_f()
4353 until then to read environment variables.
4355 The environment is protected by a CRC32 checksum. Before the monitor
4356 is relocated into RAM, as a result of a bad CRC you will be working
4357 with the compiled-in default environment - *silently*!!! [This is
4358 necessary, because the first environment variable we need is the
4359 "baudrate" setting for the console - if we have a bad CRC, we don't
4360 have any device yet where we could complain.]
4362 Note: once the monitor has been relocated, then it will complain if
4363 the default environment is used; a new CRC is computed as soon as you
4364 use the "saveenv" command to store a valid environment.
4366 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4367 Echo the inverted Ethernet link state to the fault LED.
4369 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4370 also needs to be defined.
4372 - CONFIG_SYS_FAULT_MII_ADDR:
4373 MII address of the PHY to check for the Ethernet link state.
4375 - CONFIG_NS16550_MIN_FUNCTIONS:
4376 Define this if you desire to only have use of the NS16550_init
4377 and NS16550_putc functions for the serial driver located at
4378 drivers/serial/ns16550.c. This option is useful for saving
4379 space for already greatly restricted images, including but not
4380 limited to NAND_SPL configurations.
4382 - CONFIG_DISPLAY_BOARDINFO
4383 Display information about the board that U-Boot is running on
4384 when U-Boot starts up. The board function checkboard() is called
4387 - CONFIG_DISPLAY_BOARDINFO_LATE
4388 Similar to the previous option, but display this information
4389 later, once stdio is running and output goes to the LCD, if
4392 - CONFIG_BOARD_SIZE_LIMIT:
4393 Maximum size of the U-Boot image. When defined, the
4394 build system checks that the actual size does not
4397 Low Level (hardware related) configuration options:
4398 ---------------------------------------------------
4400 - CONFIG_SYS_CACHELINE_SIZE:
4401 Cache Line Size of the CPU.
4403 - CONFIG_SYS_DEFAULT_IMMR:
4404 Default address of the IMMR after system reset.
4406 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4407 and RPXsuper) to be able to adjust the position of
4408 the IMMR register after a reset.
4410 - CONFIG_SYS_CCSRBAR_DEFAULT:
4411 Default (power-on reset) physical address of CCSR on Freescale
4414 - CONFIG_SYS_CCSRBAR:
4415 Virtual address of CCSR. On a 32-bit build, this is typically
4416 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4418 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4419 for cross-platform code that uses that macro instead.
4421 - CONFIG_SYS_CCSRBAR_PHYS:
4422 Physical address of CCSR. CCSR can be relocated to a new
4423 physical address, if desired. In this case, this macro should
4424 be set to that address. Otherwise, it should be set to the
4425 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4426 is typically relocated on 36-bit builds. It is recommended
4427 that this macro be defined via the _HIGH and _LOW macros:
4429 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4430 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4432 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4433 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4434 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4435 used in assembly code, so it must not contain typecasts or
4436 integer size suffixes (e.g. "ULL").
4438 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4439 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4440 used in assembly code, so it must not contain typecasts or
4441 integer size suffixes (e.g. "ULL").
4443 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4444 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4445 forced to a value that ensures that CCSR is not relocated.
4447 - Floppy Disk Support:
4448 CONFIG_SYS_FDC_DRIVE_NUMBER
4450 the default drive number (default value 0)
4452 CONFIG_SYS_ISA_IO_STRIDE
4454 defines the spacing between FDC chipset registers
4457 CONFIG_SYS_ISA_IO_OFFSET
4459 defines the offset of register from address. It
4460 depends on which part of the data bus is connected to
4461 the FDC chipset. (default value 0)
4463 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4464 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4467 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4468 fdc_hw_init() is called at the beginning of the FDC
4469 setup. fdc_hw_init() must be provided by the board
4470 source code. It is used to make hardware dependant
4474 Most IDE controllers were designed to be connected with PCI
4475 interface. Only few of them were designed for AHB interface.
4476 When software is doing ATA command and data transfer to
4477 IDE devices through IDE-AHB controller, some additional
4478 registers accessing to these kind of IDE-AHB controller
4481 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4482 DO NOT CHANGE unless you know exactly what you're
4483 doing! (11-4) [MPC8xx/82xx systems only]
4485 - CONFIG_SYS_INIT_RAM_ADDR:
4487 Start address of memory area that can be used for
4488 initial data and stack; please note that this must be
4489 writable memory that is working WITHOUT special
4490 initialization, i. e. you CANNOT use normal RAM which
4491 will become available only after programming the
4492 memory controller and running certain initialization
4495 U-Boot uses the following memory types:
4496 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4497 - MPC824X: data cache
4498 - PPC4xx: data cache
4500 - CONFIG_SYS_GBL_DATA_OFFSET:
4502 Offset of the initial data structure in the memory
4503 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4504 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4505 data is located at the end of the available space
4506 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4507 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4508 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4509 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4512 On the MPC824X (or other systems that use the data
4513 cache for initial memory) the address chosen for
4514 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4515 point to an otherwise UNUSED address space between
4516 the top of RAM and the start of the PCI space.
4518 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4520 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4522 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4524 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4526 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4528 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4530 - CONFIG_SYS_OR_TIMING_SDRAM:
4533 - CONFIG_SYS_MAMR_PTA:
4534 periodic timer for refresh
4536 - CONFIG_SYS_DER: Debug Event Register (37-47)
4538 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4539 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4540 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4541 CONFIG_SYS_BR1_PRELIM:
4542 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4544 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4545 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4546 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4547 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4549 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4550 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4551 Machine Mode Register and Memory Periodic Timer
4552 Prescaler definitions (SDRAM timing)
4554 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4555 enable I2C microcode relocation patch (MPC8xx);
4556 define relocation offset in DPRAM [DSP2]
4558 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4559 enable SMC microcode relocation patch (MPC8xx);
4560 define relocation offset in DPRAM [SMC1]
4562 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4563 enable SPI microcode relocation patch (MPC8xx);
4564 define relocation offset in DPRAM [SCC4]
4566 - CONFIG_SYS_USE_OSCCLK:
4567 Use OSCM clock mode on MBX8xx board. Be careful,
4568 wrong setting might damage your board. Read
4569 doc/README.MBX before setting this variable!
4571 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4572 Offset of the bootmode word in DPRAM used by post
4573 (Power On Self Tests). This definition overrides
4574 #define'd default value in commproc.h resp.
4577 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4578 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4579 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4580 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4581 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4582 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4583 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4584 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4585 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4587 - CONFIG_PCI_DISABLE_PCIE:
4588 Disable PCI-Express on systems where it is supported but not
4591 - CONFIG_PCI_ENUM_ONLY
4592 Only scan through and get the devices on the busses.
4593 Don't do any setup work, presumably because someone or
4594 something has already done it, and we don't need to do it
4595 a second time. Useful for platforms that are pre-booted
4596 by coreboot or similar.
4598 - CONFIG_PCI_INDIRECT_BRIDGE:
4599 Enable support for indirect PCI bridges.
4602 Chip has SRIO or not
4605 Board has SRIO 1 port available
4608 Board has SRIO 2 port available
4610 - CONFIG_SRIO_PCIE_BOOT_MASTER
4611 Board can support master function for Boot from SRIO and PCIE
4613 - CONFIG_SYS_SRIOn_MEM_VIRT:
4614 Virtual Address of SRIO port 'n' memory region
4616 - CONFIG_SYS_SRIOn_MEM_PHYS:
4617 Physical Address of SRIO port 'n' memory region
4619 - CONFIG_SYS_SRIOn_MEM_SIZE:
4620 Size of SRIO port 'n' memory region
4622 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4623 Defined to tell the NAND controller that the NAND chip is using
4625 Not all NAND drivers use this symbol.
4626 Example of drivers that use it:
4627 - drivers/mtd/nand/ndfc.c
4628 - drivers/mtd/nand/mxc_nand.c
4630 - CONFIG_SYS_NDFC_EBC0_CFG
4631 Sets the EBC0_CFG register for the NDFC. If not defined
4632 a default value will be used.
4635 Get DDR timing information from an I2C EEPROM. Common
4636 with pluggable memory modules such as SODIMMs
4639 I2C address of the SPD EEPROM
4641 - CONFIG_SYS_SPD_BUS_NUM
4642 If SPD EEPROM is on an I2C bus other than the first
4643 one, specify here. Note that the value must resolve
4644 to something your driver can deal with.
4646 - CONFIG_SYS_DDR_RAW_TIMING
4647 Get DDR timing information from other than SPD. Common with
4648 soldered DDR chips onboard without SPD. DDR raw timing
4649 parameters are extracted from datasheet and hard-coded into
4650 header files or board specific files.
4652 - CONFIG_FSL_DDR_INTERACTIVE
4653 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4655 - CONFIG_SYS_83XX_DDR_USES_CS0
4656 Only for 83xx systems. If specified, then DDR should
4657 be configured using CS0 and CS1 instead of CS2 and CS3.
4659 - CONFIG_ETHER_ON_FEC[12]
4660 Define to enable FEC[12] on a 8xx series processor.
4662 - CONFIG_FEC[12]_PHY
4663 Define to the hardcoded PHY address which corresponds
4664 to the given FEC; i. e.
4665 #define CONFIG_FEC1_PHY 4
4666 means that the PHY with address 4 is connected to FEC1
4668 When set to -1, means to probe for first available.
4670 - CONFIG_FEC[12]_PHY_NORXERR
4671 The PHY does not have a RXERR line (RMII only).
4672 (so program the FEC to ignore it).
4675 Enable RMII mode for all FECs.
4676 Note that this is a global option, we can't
4677 have one FEC in standard MII mode and another in RMII mode.
4679 - CONFIG_CRC32_VERIFY
4680 Add a verify option to the crc32 command.
4683 => crc32 -v <address> <count> <crc32>
4685 Where address/count indicate a memory area
4686 and crc32 is the correct crc32 which the
4690 Add the "loopw" memory command. This only takes effect if
4691 the memory commands are activated globally (CONFIG_CMD_MEM).
4694 Add the "mdc" and "mwc" memory commands. These are cyclic
4699 This command will print 4 bytes (10,11,12,13) each 500 ms.
4701 => mwc.l 100 12345678 10
4702 This command will write 12345678 to address 100 all 10 ms.
4704 This only takes effect if the memory commands are activated
4705 globally (CONFIG_CMD_MEM).
4707 - CONFIG_SKIP_LOWLEVEL_INIT
4708 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4709 low level initializations (like setting up the memory
4710 controller) are omitted and/or U-Boot does not
4711 relocate itself into RAM.
4713 Normally this variable MUST NOT be defined. The only
4714 exception is when U-Boot is loaded (to RAM) by some
4715 other boot loader or by a debugger which performs
4716 these initializations itself.
4719 Modifies the behaviour of start.S when compiling a loader
4720 that is executed before the actual U-Boot. E.g. when
4721 compiling a NAND SPL.
4724 Modifies the behaviour of start.S when compiling a loader
4725 that is executed after the SPL and before the actual U-Boot.
4726 It is loaded by the SPL.
4728 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4729 Only for 85xx systems. If this variable is specified, the section
4730 .resetvec is not kept and the section .bootpg is placed in the
4731 previous 4k of the .text section.
4733 - CONFIG_ARCH_MAP_SYSMEM
4734 Generally U-Boot (and in particular the md command) uses
4735 effective address. It is therefore not necessary to regard
4736 U-Boot address as virtual addresses that need to be translated
4737 to physical addresses. However, sandbox requires this, since
4738 it maintains its own little RAM buffer which contains all
4739 addressable memory. This option causes some memory accesses
4740 to be mapped through map_sysmem() / unmap_sysmem().
4742 - CONFIG_USE_ARCH_MEMCPY
4743 CONFIG_USE_ARCH_MEMSET
4744 If these options are used a optimized version of memcpy/memset will
4745 be used if available. These functions may be faster under some
4746 conditions but may increase the binary size.
4748 - CONFIG_X86_RESET_VECTOR
4749 If defined, the x86 reset vector code is included. This is not
4750 needed when U-Boot is running from Coreboot.
4753 Defines the MPU clock speed (in MHz).
4755 NOTE : currently only supported on AM335x platforms.
4757 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4758 Enables the RTC32K OSC on AM33xx based plattforms
4760 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4761 Option to disable subpage write in NAND driver
4762 driver that uses this:
4763 drivers/mtd/nand/davinci_nand.c
4765 Freescale QE/FMAN Firmware Support:
4766 -----------------------------------
4768 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4769 loading of "firmware", which is encoded in the QE firmware binary format.
4770 This firmware often needs to be loaded during U-Boot booting, so macros
4771 are used to identify the storage device (NOR flash, SPI, etc) and the address
4774 - CONFIG_SYS_FMAN_FW_ADDR
4775 The address in the storage device where the FMAN microcode is located. The
4776 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4779 - CONFIG_SYS_QE_FW_ADDR
4780 The address in the storage device where the QE microcode is located. The
4781 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4784 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4785 The maximum possible size of the firmware. The firmware binary format
4786 has a field that specifies the actual size of the firmware, but it
4787 might not be possible to read any part of the firmware unless some
4788 local storage is allocated to hold the entire firmware first.
4790 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4791 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4792 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4793 virtual address in NOR flash.
4795 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4796 Specifies that QE/FMAN firmware is located in NAND flash.
4797 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4799 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4800 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4801 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4803 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4804 Specifies that QE/FMAN firmware is located on the primary SPI
4805 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4807 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4808 Specifies that QE/FMAN firmware is located in the remote (master)
4809 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4810 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4811 window->master inbound window->master LAW->the ucode address in
4812 master's memory space.
4814 Freescale Layerscape Management Complex Firmware Support:
4815 ---------------------------------------------------------
4816 The Freescale Layerscape Management Complex (MC) supports the loading of
4818 This firmware often needs to be loaded during U-Boot booting, so macros
4819 are used to identify the storage device (NOR flash, SPI, etc) and the address
4822 - CONFIG_FSL_MC_ENET
4823 Enable the MC driver for Layerscape SoCs.
4825 - CONFIG_SYS_LS_MC_FW_ADDR
4826 The address in the storage device where the firmware is located. The
4827 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4830 - CONFIG_SYS_LS_MC_FW_LENGTH
4831 The maximum possible size of the firmware. The firmware binary format
4832 has a field that specifies the actual size of the firmware, but it
4833 might not be possible to read any part of the firmware unless some
4834 local storage is allocated to hold the entire firmware first.
4836 - CONFIG_SYS_LS_MC_FW_IN_NOR
4837 Specifies that MC firmware is located in NOR flash, mapped as
4838 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4839 virtual address in NOR flash.
4841 Building the Software:
4842 ======================
4844 Building U-Boot has been tested in several native build environments
4845 and in many different cross environments. Of course we cannot support
4846 all possibly existing versions of cross development tools in all
4847 (potentially obsolete) versions. In case of tool chain problems we
4848 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4849 which is extensively used to build and test U-Boot.
4851 If you are not using a native environment, it is assumed that you
4852 have GNU cross compiling tools available in your path. In this case,
4853 you must set the environment variable CROSS_COMPILE in your shell.
4854 Note that no changes to the Makefile or any other source files are
4855 necessary. For example using the ELDK on a 4xx CPU, please enter:
4857 $ CROSS_COMPILE=ppc_4xx-
4858 $ export CROSS_COMPILE
4860 Note: If you wish to generate Windows versions of the utilities in
4861 the tools directory you can use the MinGW toolchain
4862 (http://www.mingw.org). Set your HOST tools to the MinGW
4863 toolchain and execute 'make tools'. For example:
4865 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4867 Binaries such as tools/mkimage.exe will be created which can
4868 be executed on computers running Windows.
4870 U-Boot is intended to be simple to build. After installing the
4871 sources you must configure U-Boot for one specific board type. This
4876 where "NAME_defconfig" is the name of one of the existing configu-
4877 rations; see boards.cfg for supported names.
4879 Note: for some board special configuration names may exist; check if
4880 additional information is available from the board vendor; for
4881 instance, the TQM823L systems are available without (standard)
4882 or with LCD support. You can select such additional "features"
4883 when choosing the configuration, i. e.
4885 make TQM823L_defconfig
4886 - will configure for a plain TQM823L, i. e. no LCD support
4888 make TQM823L_LCD_defconfig
4889 - will configure for a TQM823L with U-Boot console on LCD
4894 Finally, type "make all", and you should get some working U-Boot
4895 images ready for download to / installation on your system:
4897 - "u-boot.bin" is a raw binary image
4898 - "u-boot" is an image in ELF binary format
4899 - "u-boot.srec" is in Motorola S-Record format
4901 By default the build is performed locally and the objects are saved
4902 in the source directory. One of the two methods can be used to change
4903 this behavior and build U-Boot to some external directory:
4905 1. Add O= to the make command line invocations:
4907 make O=/tmp/build distclean
4908 make O=/tmp/build NAME_defconfig
4909 make O=/tmp/build all
4911 2. Set environment variable BUILD_DIR to point to the desired location:
4913 export BUILD_DIR=/tmp/build
4918 Note that the command line "O=" setting overrides the BUILD_DIR environment
4922 Please be aware that the Makefiles assume you are using GNU make, so
4923 for instance on NetBSD you might need to use "gmake" instead of
4927 If the system board that you have is not listed, then you will need
4928 to port U-Boot to your hardware platform. To do this, follow these
4931 1. Add a new configuration option for your board to the toplevel
4932 "boards.cfg" file, using the existing entries as examples.
4933 Follow the instructions there to keep the boards in order.
4934 2. Create a new directory to hold your board specific code. Add any
4935 files you need. In your board directory, you will need at least
4936 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4937 3. Create a new configuration file "include/configs/<board>.h" for
4939 3. If you're porting U-Boot to a new CPU, then also create a new
4940 directory to hold your CPU specific code. Add any files you need.
4941 4. Run "make <board>_defconfig" with your new name.
4942 5. Type "make", and you should get a working "u-boot.srec" file
4943 to be installed on your target system.
4944 6. Debug and solve any problems that might arise.
4945 [Of course, this last step is much harder than it sounds.]
4948 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4949 ==============================================================
4951 If you have modified U-Boot sources (for instance added a new board
4952 or support for new devices, a new CPU, etc.) you are expected to
4953 provide feedback to the other developers. The feedback normally takes
4954 the form of a "patch", i. e. a context diff against a certain (latest
4955 official or latest in the git repository) version of U-Boot sources.
4957 But before you submit such a patch, please verify that your modifi-
4958 cation did not break existing code. At least make sure that *ALL* of
4959 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4960 just run the "MAKEALL" script, which will configure and build U-Boot
4961 for ALL supported system. Be warned, this will take a while. You can
4962 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4963 environment variable to the script, i. e. to use the ELDK cross tools
4966 CROSS_COMPILE=ppc_8xx- MAKEALL
4968 or to build on a native PowerPC system you can type
4970 CROSS_COMPILE=' ' MAKEALL
4972 When using the MAKEALL script, the default behaviour is to build
4973 U-Boot in the source directory. This location can be changed by
4974 setting the BUILD_DIR environment variable. Also, for each target
4975 built, the MAKEALL script saves two log files (<target>.ERR and
4976 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4977 location can be changed by setting the MAKEALL_LOGDIR environment
4978 variable. For example:
4980 export BUILD_DIR=/tmp/build
4981 export MAKEALL_LOGDIR=/tmp/log
4982 CROSS_COMPILE=ppc_8xx- MAKEALL
4984 With the above settings build objects are saved in the /tmp/build,
4985 log files are saved in the /tmp/log and the source tree remains clean
4986 during the whole build process.
4989 See also "U-Boot Porting Guide" below.
4992 Monitor Commands - Overview:
4993 ============================
4995 go - start application at address 'addr'
4996 run - run commands in an environment variable
4997 bootm - boot application image from memory
4998 bootp - boot image via network using BootP/TFTP protocol
4999 bootz - boot zImage from memory
5000 tftpboot- boot image via network using TFTP protocol
5001 and env variables "ipaddr" and "serverip"
5002 (and eventually "gatewayip")
5003 tftpput - upload a file via network using TFTP protocol
5004 rarpboot- boot image via network using RARP/TFTP protocol
5005 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5006 loads - load S-Record file over serial line
5007 loadb - load binary file over serial line (kermit mode)
5009 mm - memory modify (auto-incrementing)
5010 nm - memory modify (constant address)
5011 mw - memory write (fill)
5013 cmp - memory compare
5014 crc32 - checksum calculation
5015 i2c - I2C sub-system
5016 sspi - SPI utility commands
5017 base - print or set address offset
5018 printenv- print environment variables
5019 setenv - set environment variables
5020 saveenv - save environment variables to persistent storage
5021 protect - enable or disable FLASH write protection
5022 erase - erase FLASH memory
5023 flinfo - print FLASH memory information
5024 nand - NAND memory operations (see doc/README.nand)
5025 bdinfo - print Board Info structure
5026 iminfo - print header information for application image
5027 coninfo - print console devices and informations
5028 ide - IDE sub-system
5029 loop - infinite loop on address range
5030 loopw - infinite write loop on address range
5031 mtest - simple RAM test
5032 icache - enable or disable instruction cache
5033 dcache - enable or disable data cache
5034 reset - Perform RESET of the CPU
5035 echo - echo args to console
5036 version - print monitor version
5037 help - print online help
5038 ? - alias for 'help'
5041 Monitor Commands - Detailed Description:
5042 ========================================
5046 For now: just type "help <command>".
5049 Environment Variables:
5050 ======================
5052 U-Boot supports user configuration using Environment Variables which
5053 can be made persistent by saving to Flash memory.
5055 Environment Variables are set using "setenv", printed using
5056 "printenv", and saved to Flash using "saveenv". Using "setenv"
5057 without a value can be used to delete a variable from the
5058 environment. As long as you don't save the environment you are
5059 working with an in-memory copy. In case the Flash area containing the
5060 environment is erased by accident, a default environment is provided.
5062 Some configuration options can be set using Environment Variables.
5064 List of environment variables (most likely not complete):
5066 baudrate - see CONFIG_BAUDRATE
5068 bootdelay - see CONFIG_BOOTDELAY
5070 bootcmd - see CONFIG_BOOTCOMMAND
5072 bootargs - Boot arguments when booting an RTOS image
5074 bootfile - Name of the image to load with TFTP
5076 bootm_low - Memory range available for image processing in the bootm
5077 command can be restricted. This variable is given as
5078 a hexadecimal number and defines lowest address allowed
5079 for use by the bootm command. See also "bootm_size"
5080 environment variable. Address defined by "bootm_low" is
5081 also the base of the initial memory mapping for the Linux
5082 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5085 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5086 This variable is given as a hexadecimal number and it
5087 defines the size of the memory region starting at base
5088 address bootm_low that is accessible by the Linux kernel
5089 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5090 as the default value if it is defined, and bootm_size is
5093 bootm_size - Memory range available for image processing in the bootm
5094 command can be restricted. This variable is given as
5095 a hexadecimal number and defines the size of the region
5096 allowed for use by the bootm command. See also "bootm_low"
5097 environment variable.
5099 updatefile - Location of the software update file on a TFTP server, used
5100 by the automatic software update feature. Please refer to
5101 documentation in doc/README.update for more details.
5103 autoload - if set to "no" (any string beginning with 'n'),
5104 "bootp" will just load perform a lookup of the
5105 configuration from the BOOTP server, but not try to
5106 load any image using TFTP
5108 autostart - if set to "yes", an image loaded using the "bootp",
5109 "rarpboot", "tftpboot" or "diskboot" commands will
5110 be automatically started (by internally calling
5113 If set to "no", a standalone image passed to the
5114 "bootm" command will be copied to the load address
5115 (and eventually uncompressed), but NOT be started.
5116 This can be used to load and uncompress arbitrary
5119 fdt_high - if set this restricts the maximum address that the
5120 flattened device tree will be copied into upon boot.
5121 For example, if you have a system with 1 GB memory
5122 at physical address 0x10000000, while Linux kernel
5123 only recognizes the first 704 MB as low memory, you
5124 may need to set fdt_high as 0x3C000000 to have the
5125 device tree blob be copied to the maximum address
5126 of the 704 MB low memory, so that Linux kernel can
5127 access it during the boot procedure.
5129 If this is set to the special value 0xFFFFFFFF then
5130 the fdt will not be copied at all on boot. For this
5131 to work it must reside in writable memory, have
5132 sufficient padding on the end of it for u-boot to
5133 add the information it needs into it, and the memory
5134 must be accessible by the kernel.
5136 fdtcontroladdr- if set this is the address of the control flattened
5137 device tree used by U-Boot when CONFIG_OF_CONTROL is
5140 i2cfast - (PPC405GP|PPC405EP only)
5141 if set to 'y' configures Linux I2C driver for fast
5142 mode (400kHZ). This environment variable is used in
5143 initialization code. So, for changes to be effective
5144 it must be saved and board must be reset.
5146 initrd_high - restrict positioning of initrd images:
5147 If this variable is not set, initrd images will be
5148 copied to the highest possible address in RAM; this
5149 is usually what you want since it allows for
5150 maximum initrd size. If for some reason you want to
5151 make sure that the initrd image is loaded below the
5152 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5153 variable to a value of "no" or "off" or "0".
5154 Alternatively, you can set it to a maximum upper
5155 address to use (U-Boot will still check that it
5156 does not overwrite the U-Boot stack and data).
5158 For instance, when you have a system with 16 MB
5159 RAM, and want to reserve 4 MB from use by Linux,
5160 you can do this by adding "mem=12M" to the value of
5161 the "bootargs" variable. However, now you must make
5162 sure that the initrd image is placed in the first
5163 12 MB as well - this can be done with
5165 setenv initrd_high 00c00000
5167 If you set initrd_high to 0xFFFFFFFF, this is an
5168 indication to U-Boot that all addresses are legal
5169 for the Linux kernel, including addresses in flash
5170 memory. In this case U-Boot will NOT COPY the
5171 ramdisk at all. This may be useful to reduce the
5172 boot time on your system, but requires that this
5173 feature is supported by your Linux kernel.
5175 ipaddr - IP address; needed for tftpboot command
5177 loadaddr - Default load address for commands like "bootp",
5178 "rarpboot", "tftpboot", "loadb" or "diskboot"
5180 loads_echo - see CONFIG_LOADS_ECHO
5182 serverip - TFTP server IP address; needed for tftpboot command
5184 bootretry - see CONFIG_BOOT_RETRY_TIME
5186 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5188 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5190 ethprime - controls which interface is used first.
5192 ethact - controls which interface is currently active.
5193 For example you can do the following
5195 => setenv ethact FEC
5196 => ping 192.168.0.1 # traffic sent on FEC
5197 => setenv ethact SCC
5198 => ping 10.0.0.1 # traffic sent on SCC
5200 ethrotate - When set to "no" U-Boot does not go through all
5201 available network interfaces.
5202 It just stays at the currently selected interface.
5204 netretry - When set to "no" each network operation will
5205 either succeed or fail without retrying.
5206 When set to "once" the network operation will
5207 fail when all the available network interfaces
5208 are tried once without success.
5209 Useful on scripts which control the retry operation
5212 npe_ucode - set load address for the NPE microcode
5214 silent_linux - If set then linux will be told to boot silently, by
5215 changing the console to be empty. If "yes" it will be
5216 made silent. If "no" it will not be made silent. If
5217 unset, then it will be made silent if the U-Boot console
5220 tftpsrcport - If this is set, the value is used for TFTP's
5223 tftpdstport - If this is set, the value is used for TFTP's UDP
5224 destination port instead of the Well Know Port 69.
5226 tftpblocksize - Block size to use for TFTP transfers; if not set,
5227 we use the TFTP server's default block size
5229 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5230 seconds, minimum value is 1000 = 1 second). Defines
5231 when a packet is considered to be lost so it has to
5232 be retransmitted. The default is 5000 = 5 seconds.
5233 Lowering this value may make downloads succeed
5234 faster in networks with high packet loss rates or
5235 with unreliable TFTP servers.
5237 vlan - When set to a value < 4095 the traffic over
5238 Ethernet is encapsulated/received over 802.1q
5241 The following image location variables contain the location of images
5242 used in booting. The "Image" column gives the role of the image and is
5243 not an environment variable name. The other columns are environment
5244 variable names. "File Name" gives the name of the file on a TFTP
5245 server, "RAM Address" gives the location in RAM the image will be
5246 loaded to, and "Flash Location" gives the image's address in NOR
5247 flash or offset in NAND flash.
5249 *Note* - these variables don't have to be defined for all boards, some
5250 boards currenlty use other variables for these purposes, and some
5251 boards use these variables for other purposes.
5253 Image File Name RAM Address Flash Location
5254 ----- --------- ----------- --------------
5255 u-boot u-boot u-boot_addr_r u-boot_addr
5256 Linux kernel bootfile kernel_addr_r kernel_addr
5257 device tree blob fdtfile fdt_addr_r fdt_addr
5258 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5260 The following environment variables may be used and automatically
5261 updated by the network boot commands ("bootp" and "rarpboot"),
5262 depending the information provided by your boot server:
5264 bootfile - see above
5265 dnsip - IP address of your Domain Name Server
5266 dnsip2 - IP address of your secondary Domain Name Server
5267 gatewayip - IP address of the Gateway (Router) to use
5268 hostname - Target hostname
5270 netmask - Subnet Mask
5271 rootpath - Pathname of the root filesystem on the NFS server
5272 serverip - see above
5275 There are two special Environment Variables:
5277 serial# - contains hardware identification information such
5278 as type string and/or serial number
5279 ethaddr - Ethernet address
5281 These variables can be set only once (usually during manufacturing of
5282 the board). U-Boot refuses to delete or overwrite these variables
5283 once they have been set once.
5286 Further special Environment Variables:
5288 ver - Contains the U-Boot version string as printed
5289 with the "version" command. This variable is
5290 readonly (see CONFIG_VERSION_VARIABLE).
5293 Please note that changes to some configuration parameters may take
5294 only effect after the next boot (yes, that's just like Windoze :-).
5297 Callback functions for environment variables:
5298 ---------------------------------------------
5300 For some environment variables, the behavior of u-boot needs to change
5301 when their values are changed. This functionailty allows functions to
5302 be associated with arbitrary variables. On creation, overwrite, or
5303 deletion, the callback will provide the opportunity for some side
5304 effect to happen or for the change to be rejected.
5306 The callbacks are named and associated with a function using the
5307 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5309 These callbacks are associated with variables in one of two ways. The
5310 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5311 in the board configuration to a string that defines a list of
5312 associations. The list must be in the following format:
5314 entry = variable_name[:callback_name]
5317 If the callback name is not specified, then the callback is deleted.
5318 Spaces are also allowed anywhere in the list.
5320 Callbacks can also be associated by defining the ".callbacks" variable
5321 with the same list format above. Any association in ".callbacks" will
5322 override any association in the static list. You can define
5323 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5324 ".callbacks" envirnoment variable in the default or embedded environment.
5327 Command Line Parsing:
5328 =====================
5330 There are two different command line parsers available with U-Boot:
5331 the old "simple" one, and the much more powerful "hush" shell:
5333 Old, simple command line parser:
5334 --------------------------------
5336 - supports environment variables (through setenv / saveenv commands)
5337 - several commands on one line, separated by ';'
5338 - variable substitution using "... ${name} ..." syntax
5339 - special characters ('$', ';') can be escaped by prefixing with '\',
5341 setenv bootcmd bootm \${address}
5342 - You can also escape text by enclosing in single apostrophes, for example:
5343 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5348 - similar to Bourne shell, with control structures like
5349 if...then...else...fi, for...do...done; while...do...done,
5350 until...do...done, ...
5351 - supports environment ("global") variables (through setenv / saveenv
5352 commands) and local shell variables (through standard shell syntax
5353 "name=value"); only environment variables can be used with "run"
5359 (1) If a command line (or an environment variable executed by a "run"
5360 command) contains several commands separated by semicolon, and
5361 one of these commands fails, then the remaining commands will be
5364 (2) If you execute several variables with one call to run (i. e.
5365 calling run with a list of variables as arguments), any failing
5366 command will cause "run" to terminate, i. e. the remaining
5367 variables are not executed.
5369 Note for Redundant Ethernet Interfaces:
5370 =======================================
5372 Some boards come with redundant Ethernet interfaces; U-Boot supports
5373 such configurations and is capable of automatic selection of a
5374 "working" interface when needed. MAC assignment works as follows:
5376 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5377 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5378 "eth1addr" (=>eth1), "eth2addr", ...
5380 If the network interface stores some valid MAC address (for instance
5381 in SROM), this is used as default address if there is NO correspon-
5382 ding setting in the environment; if the corresponding environment
5383 variable is set, this overrides the settings in the card; that means:
5385 o If the SROM has a valid MAC address, and there is no address in the
5386 environment, the SROM's address is used.
5388 o If there is no valid address in the SROM, and a definition in the
5389 environment exists, then the value from the environment variable is
5392 o If both the SROM and the environment contain a MAC address, and
5393 both addresses are the same, this MAC address is used.
5395 o If both the SROM and the environment contain a MAC address, and the
5396 addresses differ, the value from the environment is used and a
5399 o If neither SROM nor the environment contain a MAC address, an error
5402 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5403 will be programmed into hardware as part of the initialization process. This
5404 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5405 The naming convention is as follows:
5406 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5411 U-Boot is capable of booting (and performing other auxiliary operations on)
5412 images in two formats:
5414 New uImage format (FIT)
5415 -----------------------
5417 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5418 to Flattened Device Tree). It allows the use of images with multiple
5419 components (several kernels, ramdisks, etc.), with contents protected by
5420 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5426 Old image format is based on binary files which can be basically anything,
5427 preceded by a special header; see the definitions in include/image.h for
5428 details; basically, the header defines the following image properties:
5430 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5431 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5432 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5433 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5435 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5436 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5437 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5438 * Compression Type (uncompressed, gzip, bzip2)
5444 The header is marked by a special Magic Number, and both the header
5445 and the data portions of the image are secured against corruption by
5452 Although U-Boot should support any OS or standalone application
5453 easily, the main focus has always been on Linux during the design of
5456 U-Boot includes many features that so far have been part of some
5457 special "boot loader" code within the Linux kernel. Also, any
5458 "initrd" images to be used are no longer part of one big Linux image;
5459 instead, kernel and "initrd" are separate images. This implementation
5460 serves several purposes:
5462 - the same features can be used for other OS or standalone
5463 applications (for instance: using compressed images to reduce the
5464 Flash memory footprint)
5466 - it becomes much easier to port new Linux kernel versions because
5467 lots of low-level, hardware dependent stuff are done by U-Boot
5469 - the same Linux kernel image can now be used with different "initrd"
5470 images; of course this also means that different kernel images can
5471 be run with the same "initrd". This makes testing easier (you don't
5472 have to build a new "zImage.initrd" Linux image when you just
5473 change a file in your "initrd"). Also, a field-upgrade of the
5474 software is easier now.
5480 Porting Linux to U-Boot based systems:
5481 ---------------------------------------
5483 U-Boot cannot save you from doing all the necessary modifications to
5484 configure the Linux device drivers for use with your target hardware
5485 (no, we don't intend to provide a full virtual machine interface to
5488 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5490 Just make sure your machine specific header file (for instance
5491 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5492 Information structure as we define in include/asm-<arch>/u-boot.h,
5493 and make sure that your definition of IMAP_ADDR uses the same value
5494 as your U-Boot configuration in CONFIG_SYS_IMMR.
5496 Note that U-Boot now has a driver model, a unified model for drivers.
5497 If you are adding a new driver, plumb it into driver model. If there
5498 is no uclass available, you are encouraged to create one. See
5502 Configuring the Linux kernel:
5503 -----------------------------
5505 No specific requirements for U-Boot. Make sure you have some root
5506 device (initial ramdisk, NFS) for your target system.
5509 Building a Linux Image:
5510 -----------------------
5512 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5513 not used. If you use recent kernel source, a new build target
5514 "uImage" will exist which automatically builds an image usable by
5515 U-Boot. Most older kernels also have support for a "pImage" target,
5516 which was introduced for our predecessor project PPCBoot and uses a
5517 100% compatible format.
5521 make TQM850L_defconfig
5526 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5527 encapsulate a compressed Linux kernel image with header information,
5528 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5530 * build a standard "vmlinux" kernel image (in ELF binary format):
5532 * convert the kernel into a raw binary image:
5534 ${CROSS_COMPILE}-objcopy -O binary \
5535 -R .note -R .comment \
5536 -S vmlinux linux.bin
5538 * compress the binary image:
5542 * package compressed binary image for U-Boot:
5544 mkimage -A ppc -O linux -T kernel -C gzip \
5545 -a 0 -e 0 -n "Linux Kernel Image" \
5546 -d linux.bin.gz uImage
5549 The "mkimage" tool can also be used to create ramdisk images for use
5550 with U-Boot, either separated from the Linux kernel image, or
5551 combined into one file. "mkimage" encapsulates the images with a 64
5552 byte header containing information about target architecture,
5553 operating system, image type, compression method, entry points, time
5554 stamp, CRC32 checksums, etc.
5556 "mkimage" can be called in two ways: to verify existing images and
5557 print the header information, or to build new images.
5559 In the first form (with "-l" option) mkimage lists the information
5560 contained in the header of an existing U-Boot image; this includes
5561 checksum verification:
5563 tools/mkimage -l image
5564 -l ==> list image header information
5566 The second form (with "-d" option) is used to build a U-Boot image
5567 from a "data file" which is used as image payload:
5569 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5570 -n name -d data_file image
5571 -A ==> set architecture to 'arch'
5572 -O ==> set operating system to 'os'
5573 -T ==> set image type to 'type'
5574 -C ==> set compression type 'comp'
5575 -a ==> set load address to 'addr' (hex)
5576 -e ==> set entry point to 'ep' (hex)
5577 -n ==> set image name to 'name'
5578 -d ==> use image data from 'datafile'
5580 Right now, all Linux kernels for PowerPC systems use the same load
5581 address (0x00000000), but the entry point address depends on the
5584 - 2.2.x kernels have the entry point at 0x0000000C,
5585 - 2.3.x and later kernels have the entry point at 0x00000000.
5587 So a typical call to build a U-Boot image would read:
5589 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5590 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5591 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5592 > examples/uImage.TQM850L
5593 Image Name: 2.4.4 kernel for TQM850L
5594 Created: Wed Jul 19 02:34:59 2000
5595 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5596 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5597 Load Address: 0x00000000
5598 Entry Point: 0x00000000
5600 To verify the contents of the image (or check for corruption):
5602 -> tools/mkimage -l examples/uImage.TQM850L
5603 Image Name: 2.4.4 kernel for TQM850L
5604 Created: Wed Jul 19 02:34:59 2000
5605 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5606 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5607 Load Address: 0x00000000
5608 Entry Point: 0x00000000
5610 NOTE: for embedded systems where boot time is critical you can trade
5611 speed for memory and install an UNCOMPRESSED image instead: this
5612 needs more space in Flash, but boots much faster since it does not
5613 need to be uncompressed:
5615 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5616 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5617 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5618 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5619 > examples/uImage.TQM850L-uncompressed
5620 Image Name: 2.4.4 kernel for TQM850L
5621 Created: Wed Jul 19 02:34:59 2000
5622 Image Type: PowerPC Linux Kernel Image (uncompressed)
5623 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5624 Load Address: 0x00000000
5625 Entry Point: 0x00000000
5628 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5629 when your kernel is intended to use an initial ramdisk:
5631 -> tools/mkimage -n 'Simple Ramdisk Image' \
5632 > -A ppc -O linux -T ramdisk -C gzip \
5633 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5634 Image Name: Simple Ramdisk Image
5635 Created: Wed Jan 12 14:01:50 2000
5636 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5637 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5638 Load Address: 0x00000000
5639 Entry Point: 0x00000000
5641 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5642 option performs the converse operation of the mkimage's second form (the "-d"
5643 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5646 tools/dumpimage -i image -p position data_file
5647 -i ==> extract from the 'image' a specific 'data_file', \
5648 indexed by 'position'
5651 Installing a Linux Image:
5652 -------------------------
5654 To downloading a U-Boot image over the serial (console) interface,
5655 you must convert the image to S-Record format:
5657 objcopy -I binary -O srec examples/image examples/image.srec
5659 The 'objcopy' does not understand the information in the U-Boot
5660 image header, so the resulting S-Record file will be relative to
5661 address 0x00000000. To load it to a given address, you need to
5662 specify the target address as 'offset' parameter with the 'loads'
5665 Example: install the image to address 0x40100000 (which on the
5666 TQM8xxL is in the first Flash bank):
5668 => erase 40100000 401FFFFF
5674 ## Ready for S-Record download ...
5675 ~>examples/image.srec
5676 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5678 15989 15990 15991 15992
5679 [file transfer complete]
5681 ## Start Addr = 0x00000000
5684 You can check the success of the download using the 'iminfo' command;
5685 this includes a checksum verification so you can be sure no data
5686 corruption happened:
5690 ## Checking Image at 40100000 ...
5691 Image Name: 2.2.13 for initrd on TQM850L
5692 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5693 Data Size: 335725 Bytes = 327 kB = 0 MB
5694 Load Address: 00000000
5695 Entry Point: 0000000c
5696 Verifying Checksum ... OK
5702 The "bootm" command is used to boot an application that is stored in
5703 memory (RAM or Flash). In case of a Linux kernel image, the contents
5704 of the "bootargs" environment variable is passed to the kernel as
5705 parameters. You can check and modify this variable using the
5706 "printenv" and "setenv" commands:
5709 => printenv bootargs
5710 bootargs=root=/dev/ram
5712 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5714 => printenv bootargs
5715 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5718 ## Booting Linux kernel at 40020000 ...
5719 Image Name: 2.2.13 for NFS on TQM850L
5720 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5721 Data Size: 381681 Bytes = 372 kB = 0 MB
5722 Load Address: 00000000
5723 Entry Point: 0000000c
5724 Verifying Checksum ... OK
5725 Uncompressing Kernel Image ... OK
5726 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5727 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5728 time_init: decrementer frequency = 187500000/60
5729 Calibrating delay loop... 49.77 BogoMIPS
5730 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5733 If you want to boot a Linux kernel with initial RAM disk, you pass
5734 the memory addresses of both the kernel and the initrd image (PPBCOOT
5735 format!) to the "bootm" command:
5737 => imi 40100000 40200000
5739 ## Checking Image at 40100000 ...
5740 Image Name: 2.2.13 for initrd on TQM850L
5741 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5742 Data Size: 335725 Bytes = 327 kB = 0 MB
5743 Load Address: 00000000
5744 Entry Point: 0000000c
5745 Verifying Checksum ... OK
5747 ## Checking Image at 40200000 ...
5748 Image Name: Simple Ramdisk Image
5749 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5750 Data Size: 566530 Bytes = 553 kB = 0 MB
5751 Load Address: 00000000
5752 Entry Point: 00000000
5753 Verifying Checksum ... OK
5755 => bootm 40100000 40200000
5756 ## Booting Linux kernel at 40100000 ...
5757 Image Name: 2.2.13 for initrd on TQM850L
5758 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5759 Data Size: 335725 Bytes = 327 kB = 0 MB
5760 Load Address: 00000000
5761 Entry Point: 0000000c
5762 Verifying Checksum ... OK
5763 Uncompressing Kernel Image ... OK
5764 ## Loading RAMDisk Image at 40200000 ...
5765 Image Name: Simple Ramdisk Image
5766 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5767 Data Size: 566530 Bytes = 553 kB = 0 MB
5768 Load Address: 00000000
5769 Entry Point: 00000000
5770 Verifying Checksum ... OK
5771 Loading Ramdisk ... OK
5772 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5773 Boot arguments: root=/dev/ram
5774 time_init: decrementer frequency = 187500000/60
5775 Calibrating delay loop... 49.77 BogoMIPS
5777 RAMDISK: Compressed image found at block 0
5778 VFS: Mounted root (ext2 filesystem).
5782 Boot Linux and pass a flat device tree:
5785 First, U-Boot must be compiled with the appropriate defines. See the section
5786 titled "Linux Kernel Interface" above for a more in depth explanation. The
5787 following is an example of how to start a kernel and pass an updated
5793 oft=oftrees/mpc8540ads.dtb
5794 => tftp $oftaddr $oft
5795 Speed: 1000, full duplex
5797 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5798 Filename 'oftrees/mpc8540ads.dtb'.
5799 Load address: 0x300000
5802 Bytes transferred = 4106 (100a hex)
5803 => tftp $loadaddr $bootfile
5804 Speed: 1000, full duplex
5806 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5808 Load address: 0x200000
5809 Loading:############
5811 Bytes transferred = 1029407 (fb51f hex)
5816 => bootm $loadaddr - $oftaddr
5817 ## Booting image at 00200000 ...
5818 Image Name: Linux-2.6.17-dirty
5819 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5820 Data Size: 1029343 Bytes = 1005.2 kB
5821 Load Address: 00000000
5822 Entry Point: 00000000
5823 Verifying Checksum ... OK
5824 Uncompressing Kernel Image ... OK
5825 Booting using flat device tree at 0x300000
5826 Using MPC85xx ADS machine description
5827 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5831 More About U-Boot Image Types:
5832 ------------------------------
5834 U-Boot supports the following image types:
5836 "Standalone Programs" are directly runnable in the environment
5837 provided by U-Boot; it is expected that (if they behave
5838 well) you can continue to work in U-Boot after return from
5839 the Standalone Program.
5840 "OS Kernel Images" are usually images of some Embedded OS which
5841 will take over control completely. Usually these programs
5842 will install their own set of exception handlers, device
5843 drivers, set up the MMU, etc. - this means, that you cannot
5844 expect to re-enter U-Boot except by resetting the CPU.
5845 "RAMDisk Images" are more or less just data blocks, and their
5846 parameters (address, size) are passed to an OS kernel that is
5848 "Multi-File Images" contain several images, typically an OS
5849 (Linux) kernel image and one or more data images like
5850 RAMDisks. This construct is useful for instance when you want
5851 to boot over the network using BOOTP etc., where the boot
5852 server provides just a single image file, but you want to get
5853 for instance an OS kernel and a RAMDisk image.
5855 "Multi-File Images" start with a list of image sizes, each
5856 image size (in bytes) specified by an "uint32_t" in network
5857 byte order. This list is terminated by an "(uint32_t)0".
5858 Immediately after the terminating 0 follow the images, one by
5859 one, all aligned on "uint32_t" boundaries (size rounded up to
5860 a multiple of 4 bytes).
5862 "Firmware Images" are binary images containing firmware (like
5863 U-Boot or FPGA images) which usually will be programmed to
5866 "Script files" are command sequences that will be executed by
5867 U-Boot's command interpreter; this feature is especially
5868 useful when you configure U-Boot to use a real shell (hush)
5869 as command interpreter.
5871 Booting the Linux zImage:
5872 -------------------------
5874 On some platforms, it's possible to boot Linux zImage. This is done
5875 using the "bootz" command. The syntax of "bootz" command is the same
5876 as the syntax of "bootm" command.
5878 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5879 kernel with raw initrd images. The syntax is slightly different, the
5880 address of the initrd must be augmented by it's size, in the following
5881 format: "<initrd addres>:<initrd size>".
5887 One of the features of U-Boot is that you can dynamically load and
5888 run "standalone" applications, which can use some resources of
5889 U-Boot like console I/O functions or interrupt services.
5891 Two simple examples are included with the sources:
5896 'examples/hello_world.c' contains a small "Hello World" Demo
5897 application; it is automatically compiled when you build U-Boot.
5898 It's configured to run at address 0x00040004, so you can play with it
5902 ## Ready for S-Record download ...
5903 ~>examples/hello_world.srec
5904 1 2 3 4 5 6 7 8 9 10 11 ...
5905 [file transfer complete]
5907 ## Start Addr = 0x00040004
5909 => go 40004 Hello World! This is a test.
5910 ## Starting application at 0x00040004 ...
5921 Hit any key to exit ...
5923 ## Application terminated, rc = 0x0
5925 Another example, which demonstrates how to register a CPM interrupt
5926 handler with the U-Boot code, can be found in 'examples/timer.c'.
5927 Here, a CPM timer is set up to generate an interrupt every second.
5928 The interrupt service routine is trivial, just printing a '.'
5929 character, but this is just a demo program. The application can be
5930 controlled by the following keys:
5932 ? - print current values og the CPM Timer registers
5933 b - enable interrupts and start timer
5934 e - stop timer and disable interrupts
5935 q - quit application
5938 ## Ready for S-Record download ...
5939 ~>examples/timer.srec
5940 1 2 3 4 5 6 7 8 9 10 11 ...
5941 [file transfer complete]
5943 ## Start Addr = 0x00040004
5946 ## Starting application at 0x00040004 ...
5949 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5952 [q, b, e, ?] Set interval 1000000 us
5955 [q, b, e, ?] ........
5956 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5959 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5962 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5965 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5967 [q, b, e, ?] ...Stopping timer
5969 [q, b, e, ?] ## Application terminated, rc = 0x0
5975 Over time, many people have reported problems when trying to use the
5976 "minicom" terminal emulation program for serial download. I (wd)
5977 consider minicom to be broken, and recommend not to use it. Under
5978 Unix, I recommend to use C-Kermit for general purpose use (and
5979 especially for kermit binary protocol download ("loadb" command), and
5980 use "cu" for S-Record download ("loads" command). See
5981 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5982 for help with kermit.
5985 Nevertheless, if you absolutely want to use it try adding this
5986 configuration to your "File transfer protocols" section:
5988 Name Program Name U/D FullScr IO-Red. Multi
5989 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5990 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5996 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5997 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5999 Building requires a cross environment; it is known to work on
6000 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6001 need gmake since the Makefiles are not compatible with BSD make).
6002 Note that the cross-powerpc package does not install include files;
6003 attempting to build U-Boot will fail because <machine/ansi.h> is
6004 missing. This file has to be installed and patched manually:
6006 # cd /usr/pkg/cross/powerpc-netbsd/include
6008 # ln -s powerpc machine
6009 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6010 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6012 Native builds *don't* work due to incompatibilities between native
6013 and U-Boot include files.
6015 Booting assumes that (the first part of) the image booted is a
6016 stage-2 loader which in turn loads and then invokes the kernel
6017 proper. Loader sources will eventually appear in the NetBSD source
6018 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6019 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6022 Implementation Internals:
6023 =========================
6025 The following is not intended to be a complete description of every
6026 implementation detail. However, it should help to understand the
6027 inner workings of U-Boot and make it easier to port it to custom
6031 Initial Stack, Global Data:
6032 ---------------------------
6034 The implementation of U-Boot is complicated by the fact that U-Boot
6035 starts running out of ROM (flash memory), usually without access to
6036 system RAM (because the memory controller is not initialized yet).
6037 This means that we don't have writable Data or BSS segments, and BSS
6038 is not initialized as zero. To be able to get a C environment working
6039 at all, we have to allocate at least a minimal stack. Implementation
6040 options for this are defined and restricted by the CPU used: Some CPU
6041 models provide on-chip memory (like the IMMR area on MPC8xx and
6042 MPC826x processors), on others (parts of) the data cache can be
6043 locked as (mis-) used as memory, etc.
6045 Chris Hallinan posted a good summary of these issues to the
6046 U-Boot mailing list:
6048 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6049 From: "Chris Hallinan" <clh@net1plus.com>
6050 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6053 Correct me if I'm wrong, folks, but the way I understand it
6054 is this: Using DCACHE as initial RAM for Stack, etc, does not
6055 require any physical RAM backing up the cache. The cleverness
6056 is that the cache is being used as a temporary supply of
6057 necessary storage before the SDRAM controller is setup. It's
6058 beyond the scope of this list to explain the details, but you
6059 can see how this works by studying the cache architecture and
6060 operation in the architecture and processor-specific manuals.
6062 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6063 is another option for the system designer to use as an
6064 initial stack/RAM area prior to SDRAM being available. Either
6065 option should work for you. Using CS 4 should be fine if your
6066 board designers haven't used it for something that would
6067 cause you grief during the initial boot! It is frequently not
6070 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6071 with your processor/board/system design. The default value
6072 you will find in any recent u-boot distribution in
6073 walnut.h should work for you. I'd set it to a value larger
6074 than your SDRAM module. If you have a 64MB SDRAM module, set
6075 it above 400_0000. Just make sure your board has no resources
6076 that are supposed to respond to that address! That code in
6077 start.S has been around a while and should work as is when
6078 you get the config right.
6083 It is essential to remember this, since it has some impact on the C
6084 code for the initialization procedures:
6086 * Initialized global data (data segment) is read-only. Do not attempt
6089 * Do not use any uninitialized global data (or implicitely initialized
6090 as zero data - BSS segment) at all - this is undefined, initiali-
6091 zation is performed later (when relocating to RAM).
6093 * Stack space is very limited. Avoid big data buffers or things like
6096 Having only the stack as writable memory limits means we cannot use
6097 normal global data to share information beween the code. But it
6098 turned out that the implementation of U-Boot can be greatly
6099 simplified by making a global data structure (gd_t) available to all
6100 functions. We could pass a pointer to this data as argument to _all_
6101 functions, but this would bloat the code. Instead we use a feature of
6102 the GCC compiler (Global Register Variables) to share the data: we
6103 place a pointer (gd) to the global data into a register which we
6104 reserve for this purpose.
6106 When choosing a register for such a purpose we are restricted by the
6107 relevant (E)ABI specifications for the current architecture, and by
6108 GCC's implementation.
6110 For PowerPC, the following registers have specific use:
6112 R2: reserved for system use
6113 R3-R4: parameter passing and return values
6114 R5-R10: parameter passing
6115 R13: small data area pointer
6119 (U-Boot also uses R12 as internal GOT pointer. r12
6120 is a volatile register so r12 needs to be reset when
6121 going back and forth between asm and C)
6123 ==> U-Boot will use R2 to hold a pointer to the global data
6125 Note: on PPC, we could use a static initializer (since the
6126 address of the global data structure is known at compile time),
6127 but it turned out that reserving a register results in somewhat
6128 smaller code - although the code savings are not that big (on
6129 average for all boards 752 bytes for the whole U-Boot image,
6130 624 text + 127 data).
6132 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6133 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6135 ==> U-Boot will use P3 to hold a pointer to the global data
6137 On ARM, the following registers are used:
6139 R0: function argument word/integer result
6140 R1-R3: function argument word
6141 R9: platform specific
6142 R10: stack limit (used only if stack checking is enabled)
6143 R11: argument (frame) pointer
6144 R12: temporary workspace
6147 R15: program counter
6149 ==> U-Boot will use R9 to hold a pointer to the global data
6151 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6153 On Nios II, the ABI is documented here:
6154 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6156 ==> U-Boot will use gp to hold a pointer to the global data
6158 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6159 to access small data sections, so gp is free.
6161 On NDS32, the following registers are used:
6163 R0-R1: argument/return
6165 R15: temporary register for assembler
6166 R16: trampoline register
6167 R28: frame pointer (FP)
6168 R29: global pointer (GP)
6169 R30: link register (LP)
6170 R31: stack pointer (SP)
6171 PC: program counter (PC)
6173 ==> U-Boot will use R10 to hold a pointer to the global data
6175 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6176 or current versions of GCC may "optimize" the code too much.
6181 U-Boot runs in system state and uses physical addresses, i.e. the
6182 MMU is not used either for address mapping nor for memory protection.
6184 The available memory is mapped to fixed addresses using the memory
6185 controller. In this process, a contiguous block is formed for each
6186 memory type (Flash, SDRAM, SRAM), even when it consists of several
6187 physical memory banks.
6189 U-Boot is installed in the first 128 kB of the first Flash bank (on
6190 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6191 booting and sizing and initializing DRAM, the code relocates itself
6192 to the upper end of DRAM. Immediately below the U-Boot code some
6193 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6194 configuration setting]. Below that, a structure with global Board
6195 Info data is placed, followed by the stack (growing downward).
6197 Additionally, some exception handler code is copied to the low 8 kB
6198 of DRAM (0x00000000 ... 0x00001FFF).
6200 So a typical memory configuration with 16 MB of DRAM could look like
6203 0x0000 0000 Exception Vector code
6206 0x0000 2000 Free for Application Use
6212 0x00FB FF20 Monitor Stack (Growing downward)
6213 0x00FB FFAC Board Info Data and permanent copy of global data
6214 0x00FC 0000 Malloc Arena
6217 0x00FE 0000 RAM Copy of Monitor Code
6218 ... eventually: LCD or video framebuffer
6219 ... eventually: pRAM (Protected RAM - unchanged by reset)
6220 0x00FF FFFF [End of RAM]
6223 System Initialization:
6224 ----------------------
6226 In the reset configuration, U-Boot starts at the reset entry point
6227 (on most PowerPC systems at address 0x00000100). Because of the reset
6228 configuration for CS0# this is a mirror of the onboard Flash memory.
6229 To be able to re-map memory U-Boot then jumps to its link address.
6230 To be able to implement the initialization code in C, a (small!)
6231 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6232 which provide such a feature like MPC8xx or MPC8260), or in a locked
6233 part of the data cache. After that, U-Boot initializes the CPU core,
6234 the caches and the SIU.
6236 Next, all (potentially) available memory banks are mapped using a
6237 preliminary mapping. For example, we put them on 512 MB boundaries
6238 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6239 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6240 programmed for SDRAM access. Using the temporary configuration, a
6241 simple memory test is run that determines the size of the SDRAM
6244 When there is more than one SDRAM bank, and the banks are of
6245 different size, the largest is mapped first. For equal size, the first
6246 bank (CS2#) is mapped first. The first mapping is always for address
6247 0x00000000, with any additional banks following immediately to create
6248 contiguous memory starting from 0.
6250 Then, the monitor installs itself at the upper end of the SDRAM area
6251 and allocates memory for use by malloc() and for the global Board
6252 Info data; also, the exception vector code is copied to the low RAM
6253 pages, and the final stack is set up.
6255 Only after this relocation will you have a "normal" C environment;
6256 until that you are restricted in several ways, mostly because you are
6257 running from ROM, and because the code will have to be relocated to a
6261 U-Boot Porting Guide:
6262 ----------------------
6264 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6268 int main(int argc, char *argv[])
6270 sighandler_t no_more_time;
6272 signal(SIGALRM, no_more_time);
6273 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6275 if (available_money > available_manpower) {
6276 Pay consultant to port U-Boot;
6280 Download latest U-Boot source;
6282 Subscribe to u-boot mailing list;
6285 email("Hi, I am new to U-Boot, how do I get started?");
6288 Read the README file in the top level directory;
6289 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6290 Read applicable doc/*.README;
6291 Read the source, Luke;
6292 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6295 if (available_money > toLocalCurrency ($2500))
6298 Add a lot of aggravation and time;
6300 if (a similar board exists) { /* hopefully... */
6301 cp -a board/<similar> board/<myboard>
6302 cp include/configs/<similar>.h include/configs/<myboard>.h
6304 Create your own board support subdirectory;
6305 Create your own board include/configs/<myboard>.h file;
6307 Edit new board/<myboard> files
6308 Edit new include/configs/<myboard>.h
6313 Add / modify source code;
6317 email("Hi, I am having problems...");
6319 Send patch file to the U-Boot email list;
6320 if (reasonable critiques)
6321 Incorporate improvements from email list code review;
6323 Defend code as written;
6329 void no_more_time (int sig)
6338 All contributions to U-Boot should conform to the Linux kernel
6339 coding style; see the file "Documentation/CodingStyle" and the script
6340 "scripts/Lindent" in your Linux kernel source directory.
6342 Source files originating from a different project (for example the
6343 MTD subsystem) are generally exempt from these guidelines and are not
6344 reformated to ease subsequent migration to newer versions of those
6347 Please note that U-Boot is implemented in C (and to some small parts in
6348 Assembler); no C++ is used, so please do not use C++ style comments (//)
6351 Please also stick to the following formatting rules:
6352 - remove any trailing white space
6353 - use TAB characters for indentation and vertical alignment, not spaces
6354 - make sure NOT to use DOS '\r\n' line feeds
6355 - do not add more than 2 consecutive empty lines to source files
6356 - do not add trailing empty lines to source files
6358 Submissions which do not conform to the standards may be returned
6359 with a request to reformat the changes.
6365 Since the number of patches for U-Boot is growing, we need to
6366 establish some rules. Submissions which do not conform to these rules
6367 may be rejected, even when they contain important and valuable stuff.
6369 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6371 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6372 see http://lists.denx.de/mailman/listinfo/u-boot
6374 When you send a patch, please include the following information with
6377 * For bug fixes: a description of the bug and how your patch fixes
6378 this bug. Please try to include a way of demonstrating that the
6379 patch actually fixes something.
6381 * For new features: a description of the feature and your
6384 * A CHANGELOG entry as plaintext (separate from the patch)
6386 * For major contributions, your entry to the CREDITS file
6388 * When you add support for a new board, don't forget to add a
6389 maintainer e-mail address to the boards.cfg file, too.
6391 * If your patch adds new configuration options, don't forget to
6392 document these in the README file.
6394 * The patch itself. If you are using git (which is *strongly*
6395 recommended) you can easily generate the patch using the
6396 "git format-patch". If you then use "git send-email" to send it to
6397 the U-Boot mailing list, you will avoid most of the common problems
6398 with some other mail clients.
6400 If you cannot use git, use "diff -purN OLD NEW". If your version of
6401 diff does not support these options, then get the latest version of
6404 The current directory when running this command shall be the parent
6405 directory of the U-Boot source tree (i. e. please make sure that
6406 your patch includes sufficient directory information for the
6409 We prefer patches as plain text. MIME attachments are discouraged,
6410 and compressed attachments must not be used.
6412 * If one logical set of modifications affects or creates several
6413 files, all these changes shall be submitted in a SINGLE patch file.
6415 * Changesets that contain different, unrelated modifications shall be
6416 submitted as SEPARATE patches, one patch per changeset.
6421 * Before sending the patch, run the MAKEALL script on your patched
6422 source tree and make sure that no errors or warnings are reported
6423 for any of the boards.
6425 * Keep your modifications to the necessary minimum: A patch
6426 containing several unrelated changes or arbitrary reformats will be
6427 returned with a request to re-formatting / split it.
6429 * If you modify existing code, make sure that your new code does not
6430 add to the memory footprint of the code ;-) Small is beautiful!
6431 When adding new features, these should compile conditionally only
6432 (using #ifdef), and the resulting code with the new feature
6433 disabled must not need more memory than the old code without your
6436 * Remember that there is a size limit of 100 kB per message on the
6437 u-boot mailing list. Bigger patches will be moderated. If they are
6438 reasonable and not too big, they will be acknowledged. But patches
6439 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob